Stack is a surname of Irish origin and is commonly found in county Kerry, Ireland. Variants of the name Stack include Stace, Stacey, Stacy, Stacke and De Staic. It is a baptismal name meaning "Son of Eustace", a Roman name of great antiquity.

Notable persons with this name include:

• Aindrias Stack (born 1978), Irish actor and musician
• Annie Stack (1894–??), Australian woman
• Anthony Stack (born 1961), Canadian general
• Austin Stack (1879–1929), Irish republican and politician
• Balaram Stack (born 1991), American surfer
• Brennan Stack (born 1988), Australian rules footballer
• Brian P. Stack (born 1966), American politician
• Brian Stack (born 1964), American actor, comedian and writer
• Carol Stack (born 1940), American anthropologist
• Charles Stack (disambiguation), multiple people
• Chelle Stack (born 1973), American gymnast
• Chris Stack, American actor
• Claudia Stack (born 1966), American educator, writer, documentarian and film producer
• David Stack (1957–1976), American murder victim
• Eddie Stack (1887–1958), American baseball player
• Edmund J. Stack (1874–1957), U.S. Representative from Illinois
• Edward Stack (disambiguation), multiple people
• Ella Stack (1929–2023), Australian doctor and politician
• Frank Stack (born 1937), American cartoonist
• Gael Stack (born 1941), American artist
• George Stack (born 1946), Irish Roman Catholic archbishop
• Graham Stack (disambiguation), multiple people
• Harvey G. Stack (1928–2022), American numismatist
• Jack Stack, American businessman
• James S. Stack (1852–1920), American politician
• James West Stack (1835–1919), New Zealand clergyman and author
• Jim Stack, American basketball executive
• John Stack (disambiguation)
• Jonathan Stack (born 1957), American documentary filmmaker
• Joseph Stack, American who flew an aircraft into an Austin, Texas building to attack the IRS
• Kelli Stack (born 1988), American ice hockey player
• Lee Stack (1868–1924), British army officer and administrator
• Mary Bagot Stack (1883–1935), Irish fitness pioneer
• Michael J. Stack (1888–1960), American politician
• Mike Stack (born 1963), American politician
• Neville Stack (1919–1994), senior Royal Air Force commander
• Oisín Stack, Irish actor
• Peggy Fletcher Stack, American journalist and writer
• Philip Stack (1900–1948), American poet
• Phil Stack, Australian musician
• Prunella Stack (1914–2010), British fitness pioneer and women's rights activist
• Richard Stack (died 1812), Irish author
• Robert Stack (1919–2003), American actor and television host
• Ryan Stack (born 1975), American basketball player
• Seán Stack (born 1953), Irish hurler
• Stephen Stack, Irish Gaelic footballer
• Steven Stack, American sociologist
• Timothy Stack (born 1956), American actor and screenwriter
• Tommy Stack (born 1945), Irish jockey
• William Stack (1882–1949), American actor