Williams first began her acting education in New York, earning a B.A. in Theatre Performance from Fordham University and later studying Shakespeare at Oxford University and at the British American Drama Academy in London.
Williams made her professional acting debut in the ABC daytime soap One Life to Live as Lorna Van Skyver, a role she played from 1995 to 1996. She also played Brandy Taylor on the CBS daytime soap As the World Turns from 2001 to 2002. With those experience in daytime soaps, she parlayed her talents into several primetime roles, including the leading role of Bianca on Lifetime's Monarch Cove, Claudia on five episodes of the hit series How I Met Your Mother, Shelley Long's daughter who was snubbed at the altar in the film Honeymoon with Mom, and two seasons on Comedy Central's Strangers with Candy. She also played the role of Caitlin McNabb who is a gold digger in the 2010 ABC Family TV movie Revenge of the Bridesmaids.
Williams has performed guest starring roles and recurring characters on more than two dozen shows, including The Mentalist, Rules of Engagement, Better Off Ted, Lie to Me, In Plain Sight, Two and a Half Men, My Wife and Kids, Jack & Bobby, As the World Turns, Veronica Mars and Drop Dead Diva. She has also held lead roles on numerous television pilots for every major network. In 2011, she began portraying the role of Lauren Reed on the USA Network series Fairly Legal.
In 2016, Williams was featured in Mogul's #IAmAMogul campaign for "Inspiring women to rise higher, shine brighter, and give back", as part of Women's History Month in March. She also had a guest spot on the NCIS episode "Charade" as Leah Ramsey as well as playing C.J., Steve's love interest in season two of the Netflix family sitcom Fuller House.