January Kristen Jones (born January 5, 1978) is an American actress and model. She is best known for playing Betty Draper in the television series Mad Men (2007–2015), as well as for roles as Cadence in American Wedding (2003), Elizabeth Harris in Unknown (2011), and Emma Frost in X-Men: First Class (2011). She currently stars as Melissa Shart in the Fox series The Last Man on Earth.For her work on Mad Men she has received two Golden Globe nominations and one Emmy nomination.