American actor (born 1960), known for Chicago Hope, who played Vice Admiral Katrina Cornwell, a senior Starfleet officer and former psychiatrist, in the first two seasons of Star Trek: Discovery.
Jayne Brook (born 1960) is an American actor best known as Dr Diane Grad in the medical drama Chicago Hope, with film roles in Kindergarten Cop and Gattaca.
She first appears in Star Trek: Discovery in the first-season episode Choose Your Pain as Katrina Cornwell, the admiral who oversees Captain Lorca and the war effort against the Klingons. Cornwell is captured by the Klingons in Lethe and later rescued, and she plays a central part in ending the war.
Brook returned in the second season as Cornwell confronts Section 31 and the rogue intelligence Control. The character dies saving the USS Enterprise in Such Sweet Sorrow, Part 2.