Kate Lockley was a fictional character on the WB Network television series Angel.

Introduced in Season One, she was a detective on the Los Angeles Police Department who occasionally helped out Angel, and seemed to be romantically attracted to him. She learned Angel was a vampire when her father (a retired officer) got involved in some bad business and was killed by other vampires. She immediately turned against Angel and began investigating supernatural cases, a-la Mulder. She had a very difficult time accepting that Angel's soul made him any different from other vampires. In season two, Angel recruited her to assist in uncovering the truth about zombie police officers, and this led to her being fired.

Feeling betrayed and with no future, Kate attempted to commit suicide by taking a large quantity of pills chased by liquor. She left Angel one (supposedly) last message chiding him for leading her down this path. At the time, Angel did not care. After his revelation night with Darla, Angel immediately went over to Kate's apartment and helped her to remain alive.

Her last comment was that she now believed in a higher power, because Angel was able to come into her apartment and save her without being invited. In the Buffy universe, it is impossible for a vampire to enter a private residence when he or she has not been invited in by a resident.