The project, which is being executive produced by Robert De Niro, focuses on six new recruits to the New York Police Department.
Deadline says that Sobieski has signed up to play Gen Perry.
The character is said to be a tough California girl who previously worked for the White House Colour Guard.
Sobieski recently appeared in The Good Wife and also guest starred in Drop Dead Diva. She was nominated for an Emmy and a Golden Globe for her role in the 1999 TV movie Joan Of Arc.