Ager was born in Chicago, Illinois, the sixth of nine children. Leaving school with only three years of formal high-school education, he taught himself to play the piano and embarked on a career as a musician. After spending time as an accompanist to silent movies, he moved to New York to write music. During World War I he served as a morale officer.
Ager also was a music publisher in partnership with his frequent musical collaborator, lyricist Jack Yellen. He moved to Hollywood where he made a living writing songs for film. On his death, Milton Ager was interred in the Westwood Village Memorial Park Cemetery in Los Angeles.
Ager was inducted into the Songwriters Hall of Fame in 1979.
In 2007, a revue of Ager's music called Vampin' Lady opened in New Hope, Pennsylvania, under the direction of Earl Wentz and transferred to New York City as part of the American Composer Series.
Ager's wife was columnist Cecelia Ager.
Ager was the father of columnist Shana Alexander.
Ager's niece, Joy Eden Harrison, a singer-songwriter with three albums to her credit, claims his work has been influential on her own musical career.
Among the best known Milton Ager songs are:
"Rockaway Hunt Fox Trot" (1915)
"Erin Is Calling" (1916)
"Tom, Dick and Harry and Jack" (1917)
"Everything is Peaches Down in Georgia" (1918)
"France We Have Not Forgotten You" (1918)
"Anything is Nice" (1919)
"There's a Lot of Blue-Eyed Marys Down in Maryland" (1919)
"A Young Man's Fancy" (1920)
"I'm Nobody's Baby" (1920), his first big hit
"Lovin' Sam" (1920)
"Who Cares?" (1920)
"Stay Away From Louisville Lou" (1923) [also known as "Louisville Lou (That Vampin' Lady)"
"Hard Hearted Hannah (The Vamp Of Savannah)" (1924)
"I Wonder What's Become of Sally" (1924)
"Big Bad Bill (Is Sweet William Now)" (1924)
"I Certainly Could" (1926)
"Hard-To-Get Gertie" (1926)
"Ain't She Sweet" (1927)
"I Still Love You" (1928)
"If You Don't Love Me" (1928)
"Oh Baby" (1928)
"Glad Rag Doll" (1928)
"Happy Days Are Here Again" (1929)
"I May Be Wrong" (1929)
"Some Day We'll Meet Again" (1932)
Works for Broadway include:
What's in a Name? (1920) - musical - composer
Rain or Shine (1928) - musical - co-composer
Murray Anderson's Almanac (1929) - revue - co-composer
Jaques Cattell Press: ASCAP biographical dictionary of composers, authors and publishers. Fourth edition. R. R. Bowker, New York 1980.
Stanley Sadie, H. Wiley Hitchcock (Ed.): The New Grove Dictionary of American Music. Grove's Dictionaries of Music, New York, N.Y. 1986.
Colin Larkin: The Encyclopedia of Popular Music. Third edition. Macmillan, New York, N.Y. 1998.