Born in Edmonton, Alberta and raised in Hamilton, Ontario, he is the son of professional musicians (conductor Dr. Lee Hepner and pianist Patricia Rolston).
His professional career began as a cellist at the age of 15 and transitioned to flute, clarinet, and saxophone during his studies at McMaster University (BMus 1978).
During his second residency in New York from 1996 to 2005, Hepner toured with Blood, Sweat and Tears, played in Broadway and Off-Broadway shows and in clubs with such artists as Buster Poindexter and Tom Wopat.
In 2015, he collaborated with Canadian musician Ian Thomas as arranger and conductor to develop a concert for the Hamilton Philharmonic Orchestra.
As Leader The Darcy Hepner Jazz Orchestra • Blues In Another Minute (Water Street 2010) As Sideman With The Berlin Contemporary Jazz Orchestra • The Morlocks and Other Pieces (FMP/Free Music Production 1993) With Larry Carlton • Plays the Sound of Philadelphia (335 2010) With Andy Middleton • Reinventing the World (Intuition 2003) With Ian Thomas • A Life In Song (Universal Music 2016) • How We Roll (IAN 2024) With Tom Wilson (LeE HARVeY OsMOND) • A Quite Evil (Latent Recordings 2008) • The Folk Sinner (Latent Recordings 2013) • Beautiful Scars (Latent Recordings 2015) • Symphonic Scars (TCW 2018) • Mohawk (Latent Recordings 2019)