He was an associate at McGuire Woods Battle & Boothe in Richmond, Virginia, before opening his own firm in Roanoke in 1986, where he practiced law until 2015.

[2] In October 2015, Fishwick was one of President Barack Obama's six nominees to United States Attorney posts.

[3] Fishwick was confirmed unanimously by the Senate Judicial Committee and was sworn in as the U.S. Attorney for the Western Virginia District in December 2015.

[4] Fishwick focused his efforts on persecuting violent criminals and countering the growing heroin epidemic.

[7] In 2022, he began a campaign to rename Roanoke's federal courthouse building after Reuben E. Lawson, a civil rights lawyer.