Born in Bradford, Haylock played for Huddersfield Town, Shelbourne, Linfield, Portadown, Panionios, Glenavon, Glentoran, Dundalk, Ards and Shamrock Rovers.
He made his League of Ireland debut on 14 January 1990, on loan from Huddersfield, and in his second game scored a hat trick.
Just five months later Haylock and his assistant were relieved of their duties at Farnborough[4] after a string of poor performances, including an 8–2 hammering at the hands of Truro City.
[6] Haylock then had a spell as first team coach & analyst at League Two side Exeter City,[7] before accepting the opportunity to return to manage Hayes & Yeading United in October 2015.
On 9 January 2024 he was announced as the manager of Combined Counties League Division One club Windsor.