HM Prison Thameside is a Category B men's private prison in the Thamesmead area of the Royal Borough of Greenwich, south-east London, England.

The prison was designed and constructed by Serco and opened on 30 March 2012, becoming fully operational in the autumn of 2012, with a capacity of 900.

[3][4] In January 2013, the Ministry of Justice announced that an additional houseblock would be constructed at Thameside Prison, increasing its capacity.

The report found that there was a high level of assaults and use of force, while 60% of prisoners were locked up during the working day, and some inmates spent 23 hours a day in their cells.

[6] The regimen at Thameside Prison combines work, education, vocational training, accredited offending behaviour programmes, and prisoner health and appropriate interventions.