Tessa Peake-Jones

 played Marta in The Time of the Doctor.

Although she has had a varied acting career, by far her most well-known role is that of actress (and occasional stripper) Raquel Turner in the classic sitcom Only Fools and Horses. By co-incidence, in Raquel's debut episode (1988's Christmas special Dates, broadcast exactly 25 years before The Time of the Doctor) she had mentioned that her biggest acting role to that date had been a bit part in a Doctor Who episode alongside Sylvester McCoy.