Roy Marsden (born Roy Anthony Mould; 25 June 1941[not verified in body]) is an English actor who portrayed Adam Dalgliesh in the Anglia Television dramatisations (1983–1998) of P. D. James's detective novels, and Neil Burnside in the spy drama The Sandbaggers (1979–1980).

"[This quote needs a citation] In the early 1960s, Marsden worked with the Royal Shakespeare Company and began to accumulate an extensive list of theatrical credits that include everything from Anton Chekhov and Henrik Ibsen to contemporary Soviet playwright Alexander Vampilov.

He played Neil Burnside, the dour and fiercely protective director of operations for the Secret Intelligence Service, whose character spent as much time infighting with his superiors in Whitehall and his own department as he did battling the KGB.

"[This quote needs a citation] Marsden's portrayal of Adam Dalgliesh in Anglia TV's P. D. James series spanned fifteen years.

The series began as adaptations played out in serials of five or six one-hour episodes each, which were, unusually for the time, recorded on outside broadcast videotape as opposed to film: After producer John Rosenberg died in early 1991 (during the transmission run of Devices and Desires), the format of the adaptations changed.

The final two adaptations were filmed in three one-hour episodes: The Dalgliesh role was taken by Martin Shaw when the BBC took over the rights to James's novels and produced its own series.

In 2008, he appeared in the ITV series The Palace as King Richard's private secretary, Sir Iain Ratalick.

He played Commander Haydock in the 2016 adaptation of Agatha Christie's N or M?, a three-episode part of the BBC's Partners in Crime serial.