Gordon Giffin worked for Sen. Sam Nunn, D-Georgia, soon out of law school in the 1970s, then went into law practice in Atlanta. In 1986, he joined what was then Long Aldridge & Norman (which is now Dentons).

Giffin was an energy regulatory litigator for two decades, and he also won a key case before the Georgia Supreme Court on sovereign immunity for IBM. He created the legal model for the local host entity for the 1988 Democratic National Convention in Atlanta and served as its general counsel. He also represented the Atlanta Committee for the Olympic Games in its interactions with the federal government.