Johnny Mercer was an American songwriter.

A native of Savannah, Georgia, Mercer began writing songs as a teenager. He came to New York City at age 19, where he worked initially as an actor in bit parts, and as a singer.

His first break as a songwriter came when a song for which he had written the lyric, "Out of Breath (and Scared to Death of You),” appeared in a Broadway revue called The Garrick Gaieties in 1930. In 1932, he won a singing contest and landed a job as singer with the Paul Whiteman Band. Whiteman introduced him to songwriter Hoagy Carmichael, and soon Mercer and Carmichael had a hit with their 1933 composition, "Lazybones.” Other composers quickly discovered his talent, and his career as a lyricist took off.

In 1942, together with fellow songwriter (and film producer) Buddy De Sylva and businessman Glen Wallichs, Mercer founded Capitol Records and became Capitol's first president and chief talent scout. Soon, he had signed up such performers as Stan Kenton, Nat "King" Cole, Jo Stafford, and Margaret Whiting, and by 1946 Capitol was responsible for one sixth of all records sold in the U.S.

In 1946, he won his first Academy Award, for "On The Atchison, Topeka, And Santa Fe" (music by Harry Warren), sung by Judy Garland in The Harvey Girls. His second Oscar came for "In The Cool, Cool, Cool Of The Evening" (music by Hoagy Carmichael), which Bing Crosby and Jane Wyman sang in the 1951 film Here Comes the Groom. In 1961, he wrote "Moon River" (music by Henry Mancini) for the film Breakfast at Tiffany's, winning his third Academy Award. The next year, he became the first songwriter to win a fourth Oscar, for the title song to the 1962 film Days of Wine and Roses (music by Mancini).

Mercer wrote or co-wrote hit songs in four different decades, from the 1930s through the 1960s. Among Mercer's many well-known songs are  "Goody Goody,” "I'm An Old Cowhand,” "Too Marvelous For Words,” "Jeepers Creepers,” "Hooray For Hollywood,” "Day In, Day Out,” "Fools Rush In,” "Blues In The Night,” "That Old Black Magic,” "My Shining Hour,” "One For My Baby,” "Ac-Cent-Tchu-Ate The Positive,” "Laura,”  "Out Of This World,” "Autumn Leaves,” "Something's Gotta Give,” "Satin Doll,” "Charade,” and "Summer Wind."

Mercer served as president of the Television Academy.

Mercer died on June 25, 1976 in Los Angeles, California. He was 66.