Set UIButton title UILabel font size programmatically

button.titleLabel.font = [UIFont systemFontOfSize:size];

should help

[button setFont:...] has been deprecated.

Use [button.titleLabel setFont:...] instead, for example:

[myButton.titleLabel setFont:[UIFont systemFontOfSize:10]];

You can also set the font size, and the font style using something like this. It's a little more than what you're asking for but hey, what the heck...

[myButton.titleLabel setFont:[UIFont fontWithName:@"Helvetica-Bold" size:13.0]];

And… if you're feeling frisky a list of available fonts can be found by implementing this code and then checking the output in your xCode debugger.

Code Swift 5:

func checkFontName(){    let familyNames = UIFont.familyNames    var fontNames = [String]()    for familyName in familyNames {        print("family Name: \(familyName)")        fontNames = UIFont.fontNames(forFamilyName: familyName)        for fontName in fontNames {            print("font Name: \(fontName)")                    }    }}

Code Objective-C:

NSArray *familyNames = [[NSArray alloc] initWithArray:[UIFont familyNames]];NSArray *fontNames;NSInteger indFamily, indFont;for (indFamily=0; indFamily<[familyNames count]; ++indFamily){    NSLog(@"Family name: %@", [familyNames objectAtIndex:indFamily]);    fontNames = [[NSArray alloc] initWithArray:            [UIFont fontNamesForFamilyName:            [familyNames objectAtIndex:indFamily]]];    for (indFont=0; indFont<[fontNames count]; ++indFont)    {        NSLog(@"    Font name: %@", [fontNames objectAtIndex:indFont]);    }}

Example:

2012-04-02 11:36:34.395 MyApp[3579:707] Family name: Thonburi2012-04-02 11:36:34.398 MyApp[3579:707]     Font name: Thonburi-Bold2012-04-02 11:36:34.402 MyApp[3579:707]     Font name: Thonburi2012-04-02 11:36:34.405 MyApp[3579:707] Family name: Snell Roundhand2012-04-02 11:36:34.408 MyApp[3579:707]     Font name: SnellRoundhand-Bold2012-04-02 11:36:34.411 MyApp[3579:707]     Font name: SnellRoundhand-Black2012-04-02 11:36:34.415 MyApp[3579:707]     Font name: SnellRoundhand2012-04-02 11:36:34.418 MyApp[3579:707] Family name: Academy Engraved LET2012-04-02 11:36:34.421 MyApp[3579:707]     Font name: AcademyEngravedLetPlain2012-04-02 11:36:34.424 MyApp[3579:707] Family name: Marker Felt2012-04-02 11:36:34.427 MyApp[3579:707]     Font name: MarkerFelt-Wide2012-04-02 11:36:34.430 MyApp[3579:707]     Font name: MarkerFelt-Thin2012-04-02 11:36:34.434 MyApp[3579:707] Family name: Geeza Pro2012-04-02 11:36:34.437 MyApp[3579:707]     Font name: GeezaPro-Bold2012-04-02 11:36:34.441 MyApp[3579:707]     Font name: GeezaPro2012-04-02 11:36:34.445 MyApp[3579:707] Family name: Arial Rounded MT Bold2012-04-02 11:36:34.448 MyApp[3579:707]     Font name: ArialRoundedMTBold2012-04-02 11:36:34.451 MyApp[3579:707] Family name: Trebuchet MS2012-04-02 11:36:34.455 MyApp[3579:707]     Font name: TrebuchetMS2012-04-02 11:36:34.458 MyApp[3579:707]     Font name: TrebuchetMS-Bold2012-04-02 11:36:34.461 MyApp[3579:707]     Font name: TrebuchetMS-Italic2012-04-02 11:36:34.464 MyApp[3579:707]     Font name: Trebuchet-BoldItalic2012-04-02 11:36:34.467 MyApp[3579:707] Family name: Arial2012-04-02 11:36:34.471 MyApp[3579:707]     Font name: Arial-BoldMT2012-04-02 11:36:34.474 MyApp[3579:707]     Font name: ArialMT2012-04-02 11:36:34.477 MyApp[3579:707]     Font name: Arial-ItalicMT2012-04-02 11:36:34.480 MyApp[3579:707]     Font name: Arial-BoldItalicMT2012-04-02 11:36:34.483 MyApp[3579:707] Family name: Marion2012-04-02 11:36:34.487 MyApp[3579:707]     Font name: Marion-Regular2012-04-02 11:36:34.491 MyApp[3579:707]     Font name: Marion-Bold2012-04-02 11:36:34.494 MyApp[3579:707]     Font name: Marion-Italic2012-04-02 11:36:34.503 MyApp[3579:707] Family name: Gurmukhi MN2012-04-02 11:36:34.507 MyApp[3579:707]     Font name: GurmukhiMN2012-04-02 11:36:34.511 MyApp[3579:707]     Font name: GurmukhiMN-Bold2012-04-02 11:36:34.514 MyApp[3579:707] Family name: Malayalam Sangam MN2012-04-02 11:36:34.518 MyApp[3579:707]     Font name: MalayalamSangamMN-Bold2012-04-02 11:36:34.522 MyApp[3579:707]     Font name: MalayalamSangamMN2012-04-02 11:36:34.525 MyApp[3579:707] Family name: Bradley Hand2012-04-02 11:36:34.529 MyApp[3579:707]     Font name: BradleyHandITCTT-Bold2012-04-02 11:36:34.532 MyApp[3579:707] Family name: Kannada Sangam MN2012-04-02 11:36:34.536 MyApp[3579:707]     Font name: KannadaSangamMN2012-04-02 11:36:34.540 MyApp[3579:707]     Font name: KannadaSangamMN-Bold2012-04-02 11:36:34.544 MyApp[3579:707] Family name: Bodoni 72 Oldstyle2012-04-02 11:36:34.548 MyApp[3579:707]     Font name: BodoniSvtyTwoOSITCTT-Book2012-04-02 11:36:34.552 MyApp[3579:707]     Font name: BodoniSvtyTwoOSITCTT-Bold2012-04-02 11:36:34.555 MyApp[3579:707]     Font name: BodoniSvtyTwoOSITCTT-BookIt2012-04-02 11:36:34.559 MyApp[3579:707] Family name: Cochin2012-04-02 11:36:34.562 MyApp[3579:707]     Font name: Cochin2012-04-02 11:36:34.566 MyApp[3579:707]     Font name: Cochin-BoldItalic2012-04-02 11:36:34.570 MyApp[3579:707]     Font name: Cochin-Italic2012-04-02 11:36:34.573 MyApp[3579:707]     Font name: Cochin-Bold2012-04-02 11:36:34.577 MyApp[3579:707] Family name: Sinhala Sangam MN2012-04-02 11:36:34.581 MyApp[3579:707]     Font name: SinhalaSangamMN2012-04-02 11:36:34.584 MyApp[3579:707]     Font name: SinhalaSangamMN-Bold2012-04-02 11:36:34.588 MyApp[3579:707] Family name: Hiragino Kaku Gothic ProN2012-04-02 11:36:34.592 MyApp[3579:707]     Font name: HiraKakuProN-W62012-04-02 11:36:34.596 MyApp[3579:707]     Font name: HiraKakuProN-W32012-04-02 11:36:34.599 MyApp[3579:707] Family name: Papyrus2012-04-02 11:36:34.603 MyApp[3579:707]     Font name: Papyrus-Condensed2012-04-02 11:36:34.607 MyApp[3579:707]     Font name: Papyrus2012-04-02 11:36:34.614 MyApp[3579:707] Family name: Verdana2012-04-02 11:36:34.620 MyApp[3579:707]     Font name: Verdana2012-04-02 11:36:34.626 MyApp[3579:707]     Font name: Verdana-Bold2012-04-02 11:36:34.674 MyApp[3579:707]     Font name: Verdana-BoldItalic2012-04-02 11:36:34.690 MyApp[3579:707]     Font name: Verdana-Italic2012-04-02 11:36:34.730 MyApp[3579:707] Family name: Zapf Dingbats2012-04-02 11:36:34.748 MyApp[3579:707]     Font name: ZapfDingbatsITC2012-04-02 11:36:34.752 MyApp[3579:707] Family name: Courier2012-04-02 11:36:34.757 MyApp[3579:707]     Font name: Courier-Bold2012-04-02 11:36:34.762 MyApp[3579:707]     Font name: Courier2012-04-02 11:36:34.769 MyApp[3579:707]     Font name: Courier-BoldOblique2012-04-02 11:36:34.778 MyApp[3579:707]     Font name: Courier-Oblique2012-04-02 11:36:34.786 MyApp[3579:707] Family name: Hoefler Text2012-04-02 11:36:34.793 MyApp[3579:707]     Font name: HoeflerText-Black2012-04-02 11:36:34.802 MyApp[3579:707]     Font name: HoeflerText-Italic2012-04-02 11:36:34.810 MyApp[3579:707]     Font name: HoeflerText-Regular2012-04-02 11:36:34.819 MyApp[3579:707]     Font name: HoeflerText-BlackItalic2012-04-02 11:36:34.827 MyApp[3579:707] Family name: Euphemia UCAS2012-04-02 11:36:34.836 MyApp[3579:707]     Font name: EuphemiaUCAS-Bold2012-04-02 11:36:34.843 MyApp[3579:707]     Font name: EuphemiaUCAS2012-04-02 11:36:34.848 MyApp[3579:707]     Font name: EuphemiaUCAS-Italic2012-04-02 11:36:34.853 MyApp[3579:707] Family name: Helvetica2012-04-02 11:36:34.857 MyApp[3579:707]     Font name: Helvetica-LightOblique2012-04-02 11:36:34.863 MyApp[3579:707]     Font name: Helvetica2012-04-02 11:36:34.873 MyApp[3579:707]     Font name: Helvetica-Oblique2012-04-02 11:36:34.876 MyApp[3579:707]     Font name: Helvetica-BoldOblique2012-04-02 11:36:34.880 MyApp[3579:707]     Font name: Helvetica-Bold2012-04-02 11:36:34.884 MyApp[3579:707]     Font name: Helvetica-Light2012-04-02 11:36:34.887 MyApp[3579:707] Family name: Hiragino Mincho ProN2012-04-02 11:36:34.892 MyApp[3579:707]     Font name: HiraMinProN-W32012-04-02 11:36:34.898 MyApp[3579:707]     Font name: HiraMinProN-W62012-04-02 11:36:34.902 MyApp[3579:707] Family name: Bodoni Ornaments2012-04-02 11:36:34.905 MyApp[3579:707]     Font name: BodoniOrnamentsITCTT2012-04-02 11:36:34.923 MyApp[3579:707] Family name: Apple Color Emoji2012-04-02 11:36:34.938 MyApp[3579:707]     Font name: AppleColorEmoji2012-04-02 11:36:34.942 MyApp[3579:707] Family name: Optima2012-04-02 11:36:34.946 MyApp[3579:707]     Font name: Optima-ExtraBlack2012-04-02 11:36:34.950 MyApp[3579:707]     Font name: Optima-Italic2012-04-02 11:36:34.954 MyApp[3579:707]     Font name: Optima-Regular2012-04-02 11:36:34.965 MyApp[3579:707]     Font name: Optima-BoldItalic2012-04-02 11:36:34.969 MyApp[3579:707]     Font name: Optima-Bold2012-04-02 11:36:34.972 MyApp[3579:707] Family name: Gujarati Sangam MN2012-04-02 11:36:34.985 MyApp[3579:707]     Font name: GujaratiSangamMN2012-04-02 11:36:34.989 MyApp[3579:707]     Font name: GujaratiSangamMN-Bold2012-04-02 11:36:34.993 MyApp[3579:707] Family name: Devanagari Sangam MN2012-04-02 11:36:34.998 MyApp[3579:707]     Font name: DevanagariSangamMN2012-04-02 11:36:35.002 MyApp[3579:707]     Font name: DevanagariSangamMN-Bold2012-04-02 11:36:35.006 MyApp[3579:707] Family name: Times New Roman2012-04-02 11:36:35.017 MyApp[3579:707]     Font name: TimesNewRomanPS-ItalicMT2012-04-02 11:36:35.021 MyApp[3579:707]     Font name: TimesNewRomanPS-BoldMT2012-04-02 11:36:35.032 MyApp[3579:707]     Font name: TimesNewRomanPSMT2012-04-02 11:36:35.037 MyApp[3579:707]     Font name: TimesNewRomanPS-BoldItalicMT2012-04-02 11:36:35.041 MyApp[3579:707] Family name: Kailasa2012-04-02 11:36:35.045 MyApp[3579:707]     Font name: Kailasa2012-04-02 11:36:35.050 MyApp[3579:707]     Font name: Kailasa-Bold2012-04-02 11:36:35.053 MyApp[3579:707] Family name: Telugu Sangam MN2012-04-02 11:36:35.064 MyApp[3579:707]     Font name: TeluguSangamMN-Bold2012-04-02 11:36:35.068 MyApp[3579:707]     Font name: TeluguSangamMN2012-04-02 11:36:35.071 MyApp[3579:707] Family name: Heiti SC2012-04-02 11:36:35.099 MyApp[3579:707]     Font name: STHeitiSC-Medium2012-04-02 11:36:35.107 MyApp[3579:707]     Font name: STHeitiSC-Light2012-04-02 11:36:35.111 MyApp[3579:707] Family name: Futura2012-04-02 11:36:35.115 MyApp[3579:707]     Font name: Futura-Medium2012-04-02 11:36:35.119 MyApp[3579:707]     Font name: Futura-CondensedExtraBold2012-04-02 11:36:35.122 MyApp[3579:707]     Font name: Futura-CondensedMedium2012-04-02 11:36:35.135 MyApp[3579:707]     Font name: Futura-MediumItalic2012-04-02 11:36:35.155 MyApp[3579:707] Family name: Bodoni 722012-04-02 11:36:35.160 MyApp[3579:707]     Font name: BodoniSvtyTwoITCTT-BookIta2012-04-02 11:36:35.164 MyApp[3579:707]     Font name: BodoniSvtyTwoITCTT-Book2012-04-02 11:36:35.168 MyApp[3579:707]     Font name: BodoniSvtyTwoITCTT-Bold2012-04-02 11:36:35.171 MyApp[3579:707] Family name: Baskerville2012-04-02 11:36:35.183 MyApp[3579:707]     Font name: Baskerville-SemiBoldItalic2012-04-02 11:36:35.187 MyApp[3579:707]     Font name: Baskerville-Bold2012-04-02 11:36:35.197 MyApp[3579:707]     Font name: Baskerville-Italic2012-04-02 11:36:35.245 MyApp[3579:707]     Font name: Baskerville-BoldItalic2012-04-02 11:36:35.253 MyApp[3579:707]     Font name: Baskerville-SemiBold2012-04-02 11:36:35.258 MyApp[3579:707]     Font name: Baskerville2012-04-02 11:36:35.262 MyApp[3579:707] Family name: Chalkboard SE2012-04-02 11:36:35.266 MyApp[3579:707]     Font name: ChalkboardSE-Regular2012-04-02 11:36:35.269 MyApp[3579:707]     Font name: ChalkboardSE-Bold2012-04-02 11:36:35.279 MyApp[3579:707]     Font name: ChalkboardSE-Light2012-04-02 11:36:35.284 MyApp[3579:707] Family name: Heiti TC2012-04-02 11:36:35.288 MyApp[3579:707]     Font name: STHeitiTC-Medium2012-04-02 11:36:35.299 MyApp[3579:707]     Font name: STHeitiTC-Light2012-04-02 11:36:35.305 MyApp[3579:707] Family name: Copperplate2012-04-02 11:36:35.310 MyApp[3579:707]     Font name: Copperplate2012-04-02 11:36:35.313 MyApp[3579:707]     Font name: Copperplate-Light2012-04-02 11:36:35.317 MyApp[3579:707]     Font name: Copperplate-Bold2012-04-02 11:36:35.320 MyApp[3579:707] Family name: Party LET2012-04-02 11:36:35.334 MyApp[3579:707]     Font name: PartyLetPlain2012-04-02 11:36:35.338 MyApp[3579:707] Family name: American Typewriter2012-04-02 11:36:35.351 MyApp[3579:707]     Font name: AmericanTypewriter-CondensedLight2012-04-02 11:36:35.357 MyApp[3579:707]     Font name: AmericanTypewriter-Light2012-04-02 11:36:35.361 MyApp[3579:707]     Font name: AmericanTypewriter-Bold2012-04-02 11:36:35.364 MyApp[3579:707]     Font name: AmericanTypewriter2012-04-02 11:36:35.368 MyApp[3579:707]     Font name: AmericanTypewriter-CondensedBold2012-04-02 11:36:35.372 MyApp[3579:707]     Font name: AmericanTypewriter-Condensed2012-04-02 11:36:35.384 MyApp[3579:707] Family name: AppleGothic2012-04-02 11:36:35.400 MyApp[3579:707]     Font name: AppleGothic2012-04-02 11:36:35.406 MyApp[3579:707] Family name: Bangla Sangam MN2012-04-02 11:36:35.411 MyApp[3579:707]     Font name: BanglaSangamMN-Bold2012-04-02 11:36:35.414 MyApp[3579:707]     Font name: BanglaSangamMN2012-04-02 11:36:35.418 MyApp[3579:707] Family name: Noteworthy2012-04-02 11:36:35.422 MyApp[3579:707]     Font name: Noteworthy-Light2012-04-02 11:36:35.432 MyApp[3579:707]     Font name: Noteworthy-Bold2012-04-02 11:36:35.436 MyApp[3579:707] Family name: Zapfino2012-04-02 11:36:35.443 MyApp[3579:707]     Font name: Zapfino2012-04-02 11:36:35.448 MyApp[3579:707] Family name: Tamil Sangam MN2012-04-02 11:36:35.452 MyApp[3579:707]     Font name: TamilSangamMN2012-04-02 11:36:35.456 MyApp[3579:707]     Font name: TamilSangamMN-Bold2012-04-02 11:36:35.459 MyApp[3579:707] Family name: DB LCD Temp2012-04-02 11:36:35.463 MyApp[3579:707]     Font name: DBLCDTempBlack2012-04-02 11:36:35.467 MyApp[3579:707] Family name: Arial Hebrew2012-04-02 11:36:35.471 MyApp[3579:707]     Font name: ArialHebrew2012-04-02 11:36:35.475 MyApp[3579:707]     Font name: ArialHebrew-Bold2012-04-02 11:36:35.479 MyApp[3579:707] Family name: Chalkduster2012-04-02 11:36:35.482 MyApp[3579:707]     Font name: Chalkduster2012-04-02 11:36:35.486 MyApp[3579:707] Family name: Georgia2012-04-02 11:36:35.490 MyApp[3579:707]     Font name: Georgia-Italic2012-04-02 11:36:35.493 MyApp[3579:707]     Font name: Georgia-BoldItalic2012-04-02 11:36:35.497 MyApp[3579:707]     Font name: Georgia-Bold2012-04-02 11:36:35.501 MyApp[3579:707]     Font name: Georgia2012-04-02 11:36:35.504 MyApp[3579:707] Family name: Helvetica Neue2012-04-02 11:36:35.508 MyApp[3579:707]     Font name: HelveticaNeue-Bold2012-04-02 11:36:35.511 MyApp[3579:707]     Font name: HelveticaNeue-CondensedBlack2012-04-02 11:36:35.515 MyApp[3579:707]     Font name: HelveticaNeue-Medium2012-04-02 11:36:35.518 MyApp[3579:707]     Font name: HelveticaNeue2012-04-02 11:36:35.522 MyApp[3579:707]     Font name: HelveticaNeue-Light2012-04-02 11:36:35.526 MyApp[3579:707]     Font name: HelveticaNeue-CondensedBold2012-04-02 11:36:35.529 MyApp[3579:707]     Font name: HelveticaNeue-LightItalic2012-04-02 11:36:35.532 MyApp[3579:707]     Font name: HelveticaNeue-UltraLightItalic2012-04-02 11:36:35.536 MyApp[3579:707]     Font name: HelveticaNeue-UltraLight2012-04-02 11:36:35.540 MyApp[3579:707]     Font name: HelveticaNeue-BoldItalic2012-04-02 11:36:35.543 MyApp[3579:707]     Font name: HelveticaNeue-Italic2012-04-02 11:36:35.547 MyApp[3579:707] Family name: Gill Sans2012-04-02 11:36:35.551 MyApp[3579:707]     Font name: GillSans-LightItalic2012-04-02 11:36:35.555 MyApp[3579:707]     Font name: GillSans-BoldItalic2012-04-02 11:36:35.558 MyApp[3579:707]     Font name: GillSans-Italic2012-04-02 11:36:35.562 MyApp[3579:707]     Font name: GillSans2012-04-02 11:36:35.565 MyApp[3579:707]     Font name: GillSans-Bold2012-04-02 11:36:35.569 MyApp[3579:707]     Font name: GillSans-Light2012-04-02 11:36:35.572 MyApp[3579:707] Family name: Palatino2012-04-02 11:36:35.576 MyApp[3579:707]     Font name: Palatino-Roman2012-04-02 11:36:35.580 MyApp[3579:707]     Font name: Palatino-Bold2012-04-02 11:36:35.583 MyApp[3579:707]     Font name: Palatino-BoldItalic2012-04-02 11:36:35.587 MyApp[3579:707]     Font name: Palatino-Italic2012-04-02 11:36:35.591 MyApp[3579:707] Family name: Courier New2012-04-02 11:36:35.594 MyApp[3579:707]     Font name: CourierNewPSMT2012-04-02 11:36:35.598 MyApp[3579:707]     Font name: CourierNewPS-BoldMT2012-04-02 11:36:35.601 MyApp[3579:707]     Font name: CourierNewPS-BoldItalicMT2012-04-02 11:36:35.605 MyApp[3579:707]     Font name: CourierNewPS-ItalicMT2012-04-02 11:36:35.608 MyApp[3579:707] Family name: Oriya Sangam MN2012-04-02 11:36:35.612 MyApp[3579:707]     Font name: OriyaSangamMN-Bold2012-04-02 11:36:35.616 MyApp[3579:707]     Font name: OriyaSangamMN2012-04-02 11:36:35.619 MyApp[3579:707] Family name: Didot2012-04-02 11:36:35.623 MyApp[3579:707]     Font name: Didot-Italic2012-04-02 11:36:35.627 MyApp[3579:707]     Font name: Didot2012-04-02 11:36:35.630 MyApp[3579:707]     Font name: Didot-Bold2012-04-02 11:36:35.634 MyApp[3579:707] Family name: Bodoni 72 Smallcaps2012-04-02 11:36:35.638 MyApp[3579:707]     Font name: BodoniSvtyTwoSCITCTT-Book