Kaitlin Olson
Kaitlin Willow Olson (born August 18, 1975) is an American actress. A native of Oregon, Olson studied theatre in college and began her acting career as a member of the improvisational group Groundlings in Los Angeles. She made several supporting appearances in films and television in the early 2000s before landing the role of Deandra "Sweet Dee" Reynolds on the FX black comedy series It's Always Sunny in Philadelphia, which she has starred in since 2005.