Jimmy Nielsen (born 6 August 1977) is a Danish-American retired footballer who played as a goalkeeper who most recently served as head coach of Hartford Athletic in the USL Championship.
Until June 2007, he played 398 games for Danish team AaB Fodbold.
Playing every league match for AaB since 1997, Nielsen won the 1999 Danish Superliga championship with AaB.
Nielsen has on occasion featured in the Danish national team setup as an unused substitute.
He won the 1998 and 2004 Danish Goalkeeper of the Year award.