Putnam or Puttnam is a surname. Notable people with the surnames include:

• Adam Putnam (born 1974), American politician
• Ann Putnam, Jr. (1679–1716), an accuser in the Salem witch trials
• Ashley Putnam (born 1952), American opera singer
• Benjamin Putnam (born 1981), American drag queen and comedian known as BenDeLaCreme
• Bill Putnam (1920–1989), American audio engineer
• Bill Putnam (basketball) (1922–1992), American basketball player
• Brenda Putnam (1890–1975), American sculptor
• Carleton Putnam (c. 1902–1998), American aviator, activist and author
• Charles Flint Putnam (1854–1882), US naval officer, polar explorer
• David Putnam (1898–1918), American World War I air ace
• David Puttnam (born 1941), British film producer
• Donald Fulton Putnam (fl. 1969), Canadian geographer, winner of Massey Medal
• Douglas Putnam (1838–1918), American military officer
• Edson A. Putnam (1832–1917), American politician
• Frank W. Putnam (1917–2006), American biologist
• Frederic Ward Putnam (1839–1915), American anthropologist, Harvard University
• George Putnam (1914–2008), American journalist
• George Haven Putnam (1844–1930), American book entrepreneur and publishing-family member
• George Palmer Putnam (1814–1872), American book entrepreneur
• George P. Putnam (1887–1950), American publisher, author, explorer, and publishing-family and aviation-family member
• Harvey Putnam (1793–1855), U.S. Congressman from New York
• Herbert Putnam (1861–1955), American library administrator and publishing-family member
• Hilary Putnam (1926–2016), American philosopher
• Howard Putnam (b. 1937), American travel business manager
• Israel Putnam (1718–1790), American general
• James Putnam (disambiguation), several people
• Mary Corinna Putnam Jacobi (1842–1906), American physician
• Michael Putnam (born 1983), American professional golfer
• Palmer Cosslett Putnam (1900–1984), American wind power pioneer and author, builder of the Smith–Putnam wind turbine
• Phelps Putnam (1894–1948), American poet
• Robert D. Putnam (born 1941), American political scientist
• Roger Putnam (1892–1972), American politician and industrialist
• Rufus Putnam (1738–1824), American soldier
• Ruth Putnam (disambiguation), several people
• Ruth Anna Putnam (1927–2019), American philosopher
• Seth Putnam (1968–2011), American musician
• Thomas Putnam (1651–1699), landowner and accuser in Salem, Massachusetts, during the Salem witch trials
• Tracy Putnam (1894–1975), medical researcher, co-discoverer of Phenytoin
• William Putnam (disambiguation), several people

Fictional characters

• Cecil Putnam, a character in Ninjago
• Oliver Putnam, a character portrayed by Martin Short in Only Murders in the Building