[citation needed] He first began working as a director at Ealing Studios, co-directing comedy films with Will Hay, starting with Black Sheep of Whitehall (1942).

[citation needed] Dearden worked on the influential chiller compendium Dead of Night (1945) and directed the linking narrative and the "Hearse Driver" segment.

Dearden made The Gentle Gunman (1952), an IRA thriller with Dirk Bogarde; The Square Ring (1953), a boxing film with Jack Warner; The Rainbow Jacket (1954), a horse racing drama; and Out of the Clouds (1955), set at an airport.

Dearden did some uncredited directing on The Green Man (1956) then made an Ealing style comedy for British Lion The Smallest Show on Earth (1957).

Dearden and Michael Relph made a series of films on subjects generally not tackled by British cinema in this era starting with Sapphire (1959), a thriller about race relations that proved popular.

[7] Dearden and Relph helped set up Allied Film Makers, for whom they made The League of Gentlemen (1960), a bank heist comedy that was very popular.

However, his next few movies were not popular: All Night Long (1961), an adaptation of Othello; Life for Ruth (1962), for Allied, which dealt with religious objections to operations.

Dearden and Relph then made two films for release by United Artists: Woman of Straw (1964) starring Sean Connery; and Masquerade (1965) with Cliff Robertson.

[11] Dearden died on 23 March 1971 at Hillingdon Hospital, London after being involved in a road accident on the M4 motorway near Heathrow Airport, in which he suffered multiple injuries.

He writes: "Dearden's films are decent, empty and plodding and his association with Michael Relph is a fair representative of the British preference for bureaucratic cinema.