Maryland's first female Episcopal bishop was the driver in a hit-and-run crash that killed a bicyclist in Baltimore, the diocese says.

Bishop Suffragan Heather Cook's vehicle collided with Tom Palermo, 41 on Saturday and initially left the scene.

Diocesan Bishop Eugene Sutton told clergy members in an email that Bishop Cook returned 20 minutes later "to take responsibility for her actions".

Ms Cook, who was elected bishop in September, has been put on leave.

"Together with the Diocese of Maryland, I express my deep sorrow over the death of the cyclist and offer my condolences to the victim's family," Bishop Sutton said.

"Please pray for Mr Palermo, his family and Bishop Cook during this most difficult time."

Bishop Cook was ordained priest in 1987 and served in Virginia, New York and Pennsylvania before returning to the state.

A small makeshift memorial was created near the road where Mr Palermo was killed. The road had a designated bike lane.

Police, who did not identify Ms Cook, did not say when or if charges would be filed against the driver.

Chris Merriam said Mr Palermo, a father of two, was well-known among bicyclists in the area for his custom bike frames.

"He was a craftsman," Mr Merriam said. "He was a very talented guy, and a lot of people knew him."