A. Justice, also known as Apollo Justice is a defense attorney who is a direct reference to the titular videogame character from the Ace Attorney series.
F. Reede is an attorney at law, being a reference to the fast-talking protagonist Fletcher Reede originating from the movie Liar Liar. He became a successful lawyer for lying.
F. White is a defense attorney, who defended Henry in court. And he's also a direct reference to Phoenix Wright from the Ace Attorney series. Obviously, it was changed to Felix White for copyright reasons.
Kevin Lomax is an attorney shown in the legacy version of Lawyered Up, a reference to the titular protagonist of the horror film The Devil's Advocate. He was a young yet greedy attorney at law who never lost a case.
Johnnie Cochran is an attorney seen in the legacy version as well, being a direct reference to the eponymous lawyer and civil activist.
J. Kelly is a defense attorney referencing Jack Kelly from It's Always Sunny, who is commonly shown working in his profession or performing other activities.
J. Pianta, is a judge referencing Judge Pianta from Super Mario Sunshine, who held trial for the namesake character.
M. Hyperchicken, known as Hyper-chicken in the legacy version is a defense attorney as well as a prosecutor, referencing the character of the same name from Futurama.
S. Goodman, full name Saul Goodman is a defense attorney being a reference to the titular character from Breaking Bad and Better Call Saul.