Born in Leeds, West Yorkshire, Monkhouse began his career with Rotherham United as a trainee before rising to the senior ranks at the age of 18 and scored on his debut in a 3–0 win against Hartlepool United.
After 128 league outings for Rotherham and a couple of long-term injuries. Monkhouse became Dennis Wise's first signing as manager of Swindon Town on 22 June 2006, signing a one-year contract
Monkhouse's time at Swindon was interrupted by injury and he was loaned to Hartlepool United. Following a successful loan spell, a deal was then agreed between Swindon and Hartlepool United on 10 January 2007. Remarkably, the first time he was on the losing side in a league match in 2006–07 was in United's defeat against Barnet on 7 April 2007.
Monkhouse was named in the PFA League Two Team of the Year for the 2006–07 season after Hartlepool went on to finish 2nd to secure promotion to League One.
After playing in a 1–0 win against Sheffield United in the Johnstone's Paint Trophy in October 2013, Monkhouse made his 300th appearance for Hartlepool in all competitions which made him only one of 16 Pools players to do so.