Donald Jay Fagen (born January 10, 1948) is an American musician and songwriter, best known as the co-founder (along with partner Walter Becker) and lead singer of the rock band Steely Dan.

Following the initial breakup of Steely Dan in 1981, he launched a long-running, if sporadic, solo career in 1982, spawning four albums to date. The fourth album, Sunken Condos, was released on October 16, 2012. In 1993, Fagen and Becker reunited and have since toured and released albums as Steely Dan.