Lesley Griffiths was brought up in North East Wales and has lived and worked in Wrexham all her adult life. She has 2 daughters and has served as a school governor and community councillor. She worked at the Wrexham Maelor Hospital for 20 years. Prior to her election she worked as constituency assistant to Ian Lucas, MP. As a strong supporter of devolution for Wales, she played an active role in the 1997 'Yes for Wales' campaign. She is a member of Unison.

She was elected to the National Assembly for Wales in May 2007 and served on several Assembly Committees. She set up and chaired the Cross Party Hospice Group. In December 2009, she was appointed Deputy Minister for Science, Innovation and Skills. Following re-election to the National Assembly for Wales in May 2011, Lesley Griffiths was appointed Minister for Health and Social Services and in March 2013 was appointed Minister for Local Government and Government Business. In September 2014, she was appointed Minister for Communities and Tackling Poverty. In May 2016, following re-election, she was appointed Cabinet Secretary for Environment and Rural Affairs. Lesley was appointed Cabinet Secretary for Energy, Planning and Rural Affairs on 3 November 2017. On 13 December 2018 Lesley was appointed Minister for Environment, Energy and Rural Affairs.

Outside of politics, her main hobbies are music, walking and watching Wrexham Football Club. Lesley is formerly an elected director of the Wrexham Supporters Trust.