Sophie Burns, played by Laura Leighton is a recurring character seen on Beverly Hills, 90210, the first series of the Beverly Hills, 90210 continuity.
Sophie was a less-than-honest aspiring actress who appeared in the ninth season, when she befriended and briefly lived with Steve Sanders. Despite knowing that Steve had a crush on Sophie, a reluctant David began a secret relationship with her. Once this matter was unveiled, the friendship between the two men became briefly strained. Ultimately, though, the two made up while talking the issue out, with David declaring that the long-standing friendship was more important to him. At this point, Sophie had left both of their lives and continued her show business pursuits.
The casting of Laura Leighton in the role is a bizarre move by the producers as she had already made a name for herself playing a lead-role in 90210's spinoff, Melrose Place. It can be assumed that Melrose Place and 90210 are set in the same universe, as it was an arc of three cross-over episodes that setup Melrose Place.
After it is revealed in Melrose Place's 2009 reboot that Sydney was indeed alive, having faked her death in 1997, rumours sparked that Sophie could have been Sydney all along.