Lancaster was born in Tacoma, Washington. She attended Franklin Pierce High School in Tacoma. In 1998, she won the title of Miss Washington Teen USA. She went on to join the Sea Gals, the cheerleading squad of the Seattle Seahawks football team. Lancaster was a member of the Sea Gals for five seasons before moving to Los Angeles to pursue her acting and modeling career.
In 2003, Lancaster was a contestant on the short-lived reality show Are You Hot?: The Search for America's Sexiest People. Lancaster appeared in the music video for Bo Bice's song "The Real Thing".
In 2007, she made an appearance at the 2007 Scream Awards.
In 2008, Lancaster joined the cast of The Price Is Right as one of the show’s models.
In 2009, she was a trophy holder at the 61st Primetime Emmy Awards. Lancaster now appears in the MTV comedy series The Hard Times of RJ Berger airing in 2010 as Jenny Swanson.