American jazz bassist.
Married to Canadian-born jazz singer Anna-Lisa, and sister-in-law to Lullaby Baxter.

Kirby was born in Maumee Valley, Ohio, and his family moved to St. Louis when he was two. He began playing guitar and bass guitar while stationed at Fort Bragg, and following this he attended Webster University, receiving his degree in 1985. He worked in ensembles and then got his master's degree at the Manhattan School of Music, where he played with Lester Bowie. In 1988 he returned to Webster, where he taught until 1993.

In January 2017, Kirby released All Over the Map, his first orchestral recording featuring his compositions. Kirby appeared as a leader on the albums Wicked Grin (2008) and Stepchild (2013), featuring the University of Manitoba Jazz Faculty Ensemble. He spent 15 years heading the University of Manitoba Jazz Studies program.