Arts and entertainment

• Brooklyn Decker, an American model
• Carol Decker, English recording artist
• Cora Decker Sargent (1868-1944), American composer
• Daniel Decker, Puerto Rican composer
• Frank Duveneck, American figure and portrait painter.
• Frans Decker (1684 – 1751), Dutch painter
• Franz-Paul Decker (1923–2014), German conductor
• Georg Decker (1818–1894), an Austrian portrait artist
• Hans Decker, German sculptor of the fifteenth century
• Jennifer Decker, a French actress
• Johann Stephan Decker (1784–1844), French painter
• John Decker (artist) (1895–1947), German painter, set designer and caricaturist in Hollywood
• Lindsey Decker (1923–1994), American artist
• Mary Beth Decker (b. 1981), American model
• Richard Decker, cartoonist in The New Yorker
• Jorel Decker, musical artist in the band Hollywood Undead

Government and politics

• Bob Decker (1922-1999), American politician and educator
• Edward Decker (1827–1911), American businessman and politician in Kewaunee County, Wisconsin
• Eileen M. Decker, American lawyer
• George Decker, American Chief of Staff of the United States Army
• Grant Decker, American politician
• James Eric (Bill) Decker (1898–1970), Sheriff of Dallas, Texas during the assassination of John F. Kennedy
• John Decker (fire chief) (1823–1892), American businessman, politician and firefighter
• John A. Decker (died 2006), American Chief Judge of the Wisconsin Court of Appeals
• Michael P. Decker, American politician
• Wilhelm Decker, German publicist

Sports

Other

• Almarian Decker, American electrical engineer
• Ed Decker, American evangelist
• John Decker (fire chief) (1823–1892), American businessman, politician and firefighter
• Karl Decker (1897–1945), German general
• Matthew Decker, Dutch-born English merchant and writer
• Scott Decker, American criminologist
• Susan Decker, American corporate executive