The daughter of an electrician, Heidi Alexander was born in Swindon, Wiltshire, and attended the town's Churchfields Comprehensive School. She went on to study at Durham University where she received a BA in Geography and a Masters in European Urban and Regional Change.
Heidi Alexander was elected to Lewisham London Borough Council as a councillor for the Evelyn ward in 2004, and served as Deputy Mayor of Lewisham and Cabinet Member for regeneration from 2006. She was selected as the Labour Parliamentary Candidate for Lewisham East in October 2009 and was elected to Parliament in 2010.
She was a member of the Communities and Local Government Select Committee and supported Andy Burnham for the Labour leadership in 2010. Early in her parliamentary career she served as theParliamentary Private Secretary to the Shadow Secretary of State for Environment, Food and Rural Affairs Mary Creagh MP and from 2012 serves as an Opposition Whip as well as (from December 2013) a Shadow Minister for London. She is the Chair of the APPG on Choice at the End of Life.