McEvoy moved to London in 2010 to work for Jenny Chapman, the former MP for Darlington, as a parliamentary assistant.[7] She later worked as a campaign organiser for Thurrock Labour Party. In 2012, McEvoy volunteered on President Barack Obama'sre-election campaign.[3]
In 2016, McEvoy joined the Living Wage Foundation, where she managed the foundation's campaigns and communications strategy.[6] She also oversaw the Living Wage Week. McEvoy then worked as a GMB union organiser until her election to Parliament in 2024.[8]
Ahead of the 2024 general election, McEvoy was selected as the prospective Labour candidate for Darlington. She was elected as MP with 39.2% of the vote and a majority of 2,298.