Barnsley East is a constituency^{[n 1]} in South Yorkshire,^{[n 2]} represented since 2017 by Stephanie Peacock of the Labour Party.

Further to the completion of the 2023 Periodic Review of Westminster constituencies, the seat will be subject to boundary changes. As a consequence, it will be renamed Barnsley South, to be first contested at the next general election.^[3]

The seat covers the south-east suburbs of Barnsley and former coal mining areas such as Hoyland, Darfield and Wombwell. Its residents are poorer than the UK average.^[4]

The seat was created as Barnsley East in 1983 and later abolished in 1997 to create Barnsley East and Mexborough. It was recreated as Barnsley East at the 2010 general election.

Eight candidates competed for the seat in the 2010 general election; however, the largest two opposition parties failed to gain more than 18.2% each and the winning candidate Michael Dugher managed to obtain 47% of all votes despite the presence of a candidate from the Socialist Labour Party. Although the percentage decline in the Labour vote was the largest in the country (at nearly 24%), they still won the seat safely. In 2017, Stephanie Peacock succeeded Dugher as MP for Barnsley East.

Both between 1983 and 1997, and at the 2010 general election, this constituency has been a safe seat for the Labour Party, as indeed was its temporary replacement, Barnsley East and Mexborough. After the 2019 general election however, this constituency became a marginal seat, with Labour's vote share dropping by 21.9% and their majority cut to just 8.4%.

1983–1997: The Metropolitan Borough of Barnsley wards of Brierley, Cudworth, Darfield, Dearne South, Dearne Thurnscoe, Wombwell North, and Wombwell South.

2010–present: The Metropolitan Borough of Barnsley wards of Cudworth, Darfield, Hoyland Milton, North East, Rockingham, Stairfoot, Wombwell, and Worsbrough.

Following their review of parliamentary representation in South Yorkshire for the 2010 general election, the Boundary Commission for England divided the existing Barnsley East and Mexborough seat to split off Barnsley East from Mexborough, to create the new Barnsley East constituency.

• List of parliamentary constituencies in South Yorkshire