Tiffani Amber Thiessen is an American actress. She is known for playing Kelly Kapowski in Saved by the Bell and Valerie Malone in Beverly Hills, 90210. She also starred in Fastlane as Wilhelmina 'Billie' Chambers. Her most recent recurring role is as Elizabeth Burke in the USA Network television series White Collar. After many years of going by her full name, she dropped her middle name and is now credited as simply Tiffani Thiessen.