A. L. Diamond (born Ițec (Itzek) Domnici; June 27, 1920 – April 21, 1988) was a Romanian–American screenwriter, best known for his collaborations with Billy Wilder.

[1] Diamond was referred to as "Iz" in Hollywood, and was known to quip that his initials stood for "Interscholastic Algebra League", a prize he also won while attending Boys' High School.

A succession of limited-term contracts ensued, notably at Paramount, where Diamond worked on projects without receiving a writing credit.

They later wrote the classic films, Some Like It Hot, The Apartment (which won an Academy Award for Best Original Screenplay),[1] One, Two, Three, Irma la Douce, Kiss Me, Stupid and The Private Life of Sherlock Holmes.

[2] In 1980, Diamond and Wilder received the Writers Guild of America's Laurel Award for career achievement in screenwriting.