Pools have not released details of Harewood's signing, but the 34-year-old was a free agent following his release from Bristol City two weeks ago and will go straight into Colin Cooper's squad for Saturday's league game at Fleetwood.
Harewood started his career at Forest and scored over 50 goals in nearly 200 appearances before moving to West Ham in a B£500,000 deal in 2003.
He hit the target on 56 occasions in over 170 appearances for the Hammers and then moved to Aston Villa for B£4million in July 2007.
But Harewood made only one Premier League start in three years at Villa Park and after loan spells at Newcastle and Wolves joined Blackpool on a free transfer in August 2010.
The Hampstead-born forward was restricted to 16 appearances for Blackpool and then enjoyed a second stint at Forest and a spell at Barnsley before moving on to Ashton Gate.
- Sports & Recreation