President Obama nominated Gee, the daughter of immigrants from a small village in southern China, in August. The Senate confirmed her nomination on Christmas Eve.
Sen. Barbara Boxer (D-Calif.) praised her confirmation.
"As a daughter of immigrants from rural China, she personifies the American dream," Boxer said in a statement. "She used her position as a prominent attorney in Los Angeles to promote racial tolerance and fight for justice for those who face discrimination."
Gee's father was a World War II veteran who later worked as an aerospace engineer on projects including the space shuttle and the Apollo missions, according to a statement released by Boxer's office.
"Dolly's mother… was a garment worker who never taught Dolly to sew because she did not want her daughter to have to stitch clothes for a living," Boxer said at a confirmation hearing.
In 1994, President Clinton appointed Gee, who has specialized in labor and employment law, to serve as a mediator and arbitrator in disputes between federal agencies and labor unions. Clinton also nominated her for the federal bench in 1999, but she was unable to win confirmation from a gridlocked Senate before he left office.
She is a past president of the Southern California Chinese Lawyers Assn.