|Date of birth||9 December 1961|
|Place of birth||Newcastle upon Tyne, England|
|1986||→ Burnley (loan)||7||(0)|
|* Senior club appearances and goals counted for the domestic league only.
Haddock was born in Newcastle upon Tyne, and joined his home-town club as an apprentice in 1978, turning professional the following year. He made his debut in the Football League on 5 September 1981 in a 3–0 defeat at Queens Park Rangers in the Second Division. He played in a calm and collected manner and got a good run in the side during 1981–82 but lost his place halfway through the following season. He remained at the club, playing only infrequently, and had a spell on loan at Burnley, before leaving for Leeds United in July 1986 for a fee of £45,000.
During the early part of his career at Leeds he suffered a series of injuries, limiting his first-team appearances. However once he had returned he won player of the year in 1988. Under the stewardship of Howard Wilkinson "Fish", as he was known, became a crucial part of the defensive unit alongside Chris Fairclough that won promotion as Second Division champions in 1989–90. His career was cut short however when he suffered a freak injury in the second leg of the League Cup semi-final against Manchester United in 1991, as Leeds went out 3–1 on aggregate.
- "Peter Haddock". UK A–Z Transfers. Neil Brown. Retrieved 17 February 2010.
- "Peter Haddock". Toon1892. Retrieved 17 February 2010.
- Hugman, Barry (2005). The PFA Premier and Football League Players' Records 1946–2005. Queen Anne Press. ISBN 1-85291-665-6.
- "Player of the Year". Leeds United A.F.C. Archived from the original on 11 March 2005. Retrieved 17 February 2010.
- "Peter Haddock". Leeds United A.F.C. Archived from the original on 16 May 2006. Retrieved 17 February 2010.
- Interview with Haddock at The Square Ball fansite