Surname

• Alan J. Lacy (born 1953), American businessman
• Antonio Lacy (born 1957), Spanish doctor and surgeon
• Arthur J. Lacy (1876–1975), American politician and lawyer
• Benjamin W. Lacy (1839–1895), American lawyer
• Bill Lacy, U.S. political operative and business executive
• Bill N. Lacy, U.S. architect
• Bo Lacy (born 1980), American football player
• Charles L. Lacy (1885–1942), American politician
• Chris Lacy (born 1996), American football player
• David Lacy, Scottish theologian
• Ed Lacy (1911–1968), American mystery writer
• Eddie Lacy (born 1990), American football player
• Edgar Lacy (1944–2011), American basketball player
• Elizabeth B. Lacy (born 1945), American lawyer
• Fanny E. Lacy (c. 1786–1869), British writer and activist
• Franz Moritz von Lacy (1725–1801), Austrian field marshal
• George Carleton Lacy (1888–1951), American Methodist Bishop
• Gilbert Lacy (1834–1878), English cricketer
• Harriette Deborah Lacy (1807–1874), English actress
• Henry de Lacy, Earl of Lincoln (1251–1311)
• Hugh De Lacy (1910–1986), American politician
• James Lacy (actor) (1696–1774), British stage actor and theatre manager
• James T. Lacy, American politician in Virginia
• Jim Lacy, American basketball player
• Jeff Lacy (born 1977), American boxer
• Jennifer Lacy (born 1983), American basketball player
• Jerry Lacy (born 1936), American soap opera actor
• John Lacy (1615?–1681) English comic actor and playwright
• John Lacy (born 1951) English footballer
• Kerry Lacy, American relief pitcher
• Kewan Lacy (born 2006), American football player
• Kyren Lacy (2000–2025), American football player
• Lee Lacy (born 1948), American baseball player
• Len Lacy (1900–1998), member of the Louisiana House of Representatives
• Maurice Lacy (general) (1740–1820), Irish-born Russian general
• Michael Rophino Lacy (1795–1867), Irish musician
• Norman Lacy (born 1941), Australian politician
• Paul Eston Lacy (1924–2005), U.S. pathologist
• Peter von Lacy (1678–1751), Russian commander
• Philippe De Lacy (1917–1995), American silent film era child actor
• Preston Lacy (born 1969), American actor
• Roger de Lacy (died after 1106), Norman nobleman
• Sterling Byrd Lacy, American politician
• Steve Lacy (disambiguation), several people
• Suzanne Lacy (born 1945), American artist
• Tania Lacy (born 1965), Australian comedian
• Thomas Hailes Lacy (1809–1873) British actor, playwright, theatrical manager, bookseller, and theatrical publisher
• Thomas J. Lacy (c. 1806–1849), justice of the Arkansas Supreme Court
• Tyler Lacy (born 1999), American football player
• Venus Lacy (born 1967), American basketball player
• Walter Lacy (1809–1898), English actor
• William Lacy (died 1582), English martyr
• William Henry Lacy (1888–1925), American Methodist missionary to China
• William H. Lacy Jr. (1945–2016), American businessman

Given name

Men

• Lacy Banks (1943–2012), American sportswriter
• Lacy Clay (born 1956), U.S. Representative from Missouri's 1st congressional district
• Lacy Dock (1896–1963), American baseball player
• Lacy Gibson (1936–2011), American blues guitarist, singer, and songwriter
• Lacy Hunt, American economist
• Lacy Irvine Moffett (1878–1957), American Presbyterian missionary minister to China, and photographer
• Lacy Landers (1927–2011), American politician
• Lacy Overby (1920–1994), American virologist
• Lacy Ryan (c. 1694–1760), English actor
• Lacy Thornburg (born 1929), American lawyer and retired United States District Judge
• Lacy Walter Giles Yea (1808–1855), British Army colonel

Women

• Lacy Barnes-Mileham (born 1964), American discus throw track and field champion
• Lacy Crawford, American author, journalist, novelist, and memoirist
• Lacy Dagen (born 1997), American collegiate artistic gymnast
• Lacy Duarte (1937–2015), Uruguayan visual artist
• Lacy J. Dalton (born 1946), American country music singer and songwriter
• Lacy J. Davis, American writer and body image activist
• Lacy Janson (born 1983), American track and field athlete
• Lacy M. Johnson (born 1978), American writer, professor, and activist
• Lacy Schnoor (born 1985), American freestyle skier