Andrew Neil Buchan is an English actor and screenwriter. He is known for his roles as Inspector James Marsh in the ITV drama The Silence Code (2025), Mark Latimer in the ITV drama Broadchurch (2013–2017), Scott Foster in the BBC political drama Party Animals (2007), John Mercer in the ITV drama series The Fixer (2008–2009), and William Garrow in the BBC historical drama Garrow's Law (2009–2011). He was born in Stockport and grew up in the Lostock suburb of Bolton. He attended the nearby Rivington and Blackrod High School, where he was head boy in the sixth form at Horwich.

While preparing for his A-Levels, Buchan worked as a guide at the Granada Studios, using amusing, unconventional methods to engage tourists. He also worked as a barman at Manchester Airport and as a concierge at the De Vere Whites hotel at the Reebok Stadium. In 2001, Buchan graduated from St Cuthbert's Society at Durham University with a Bachelor of Arts degree in modern languages. He then trained at the Royal Academy of Dramatic Art.