Howitt was born on 5 May 1957, the son of Frank Howitt, a renowned Fleet Street journalist who, in 1963, broke the infamous Profumo Scandal by getting the exclusive story from call girl Christine Keeler of her illicit affair with a high ranking government minister.
Howitt grew up in Eltham, London in Tarnwood Park and Bromley, Kent.
Howitt's first notable TV role was in the 1984–85 series of Yorkshire Television's long-running programme for schools How We Used To Live, where he starred alongside Brookside actress Sue Jenkins.
Since then, he has directed several films, including Antitrust (2001), Johnny English (2003), Laws of Attraction (2004), and Dangerous Parking (2008).
He adapted the latter film from the novel by Stuart Browne, as well as produced and directed it, and played the lead role.