Kermode, 50, will replace Philip French, who will be retiring at the beginning of September shortly after his 80th birthday, having written for The Observer for 50 years.
Mark Kermode has written for The Observer for over a decade - his first film review for The Observer was published in 2002 and in recent years he has written a weekly DVD review column.
Mark Kermode said: "I'm honoured and thrilled to be taking over as film critic for The Observer. The paper is second to none, and writing for it has always been a privilege and a joy.
"When I first started working as a film critic over twenty five years ago, Philip's Observer reviews were an inspiration. No-one can match his breadth of knowledge or elegance of expression, but I hope I can bring to the role the passion for cinema which Observer readers expect.
"Movies have been the single overwhelming obsession of my life, and the professional film critic's trade is one of which I am fiercely proud. Philip said to me recently, 'For people in our line of work, the Observer is the best chair in the world'. As always, he is absolutely right."
About Mark Kermode
According to The Observer: Mark Kermode started writing magazine film reviews in the mid-1980s. In addition to his work for The Observer, he is currently a contributing editor to Sight & Sound.
Mark presents the Sony Award-winning 'Kermode and Mayo's Film Review' on BBC Radio 5Live, and 'The Film Review' on the BBC News Channel. He is also a presenter for BBC2's 'The Culture Show' and writes and presents the bi-weekly BBC video-blog 'Kermode Uncut'.
He has written several books on cinema and his most recent work - 'Hatchet Job – Love Movies, Hate Critics' - is published by Picador in October.
