The sci-fi drama, from Cougar Town writer Michael McDonald, is set in a future world in which humans co-exist with life-like androids.
American Horror Story's Frances Conroy, Primeval star James Murray and Royal Pains actor Patrick Heusinger are already attached to the project.
Andrea Parker, Jud Tylor, Megalyn Echikunwoke, Madisen Beaty and Cody Christian have now joined the cast, according to Deadline.
Desperate Housewives actress Parker will play Roberta, a wealthy woman who learns that her teenage daughter - The Curious Case of Benjamin Button star Beaty - is dating an android, played by Pretty Little Liars star Christian.
That '70s Show's Tylor will portray the mother of Christian's 'Mechanical', while former CSI: Miami star Echikunwoke will play the boss of attorney Gregory (Murray).
House of Lies director Stephen Hopkins will helm the Beautiful People pilot, which will be co-produced by ABC Studios and Universal TV.
Other drama projects in development at NBC include a "young, sexy and supernatural" Dracula update, legal drama Major Crimes and soap Palm Beach.