Derby South (/ˈdɑːrbi/) is a constituency^{[n 1]} formed of part of the city of Derby represented in the House of Commons of the UK Parliament since 1983 by veteran MP Margaret Beckett of the Labour Party. She has served under the Labour governments of Harold Wilson, James Callaghan, Tony Blair and Gordon Brown. She became interim Leader of the Labour Party in 1994 when John Smith suddenly died. She has also served under Neil Kinnock and Smith himself.^{[n 2]}

1950–1955: The County Borough of Derby wards of Alvaston, Arboretum, Castle, Dale, Litchurch, Normanton, Osmaston, and Peartree.

1955–1974: The County Borough of Derby wards of Alvaston, Arboretum, Castle, Dale, Litchurch, Normanton, Osmaston, and Peartree, and the parish of Littleover in the Rural District of Shardlow.

1974–1977: The Borough of Derby wards of Alvaston, Arboretum, Babington, Chellaston, Litchurch, Littleover, Normanton, Osmaston, and Peartree.

1977–1983: The City of Derby wards of Alvaston, Arboretum, Babington, Chellaston, Litchurch, Littleover, Normanton, Osmaston, and Peartree.

1983–1997: The City of Derby wards of Alvaston, Babington, Blagreaves, Kingsway, Litchurch, Littleover, Normanton, Osmaston, and Sinfin.

1997–2010: The City of Derby wards of Alvaston, Babington, Blagreaves, Kingsway, Litchurch, Littleover, Mickleover, Normanton, Osmaston, and Sinfin.

2010–2023: The City of Derby wards of Alvaston, Arboretum, Blagreaves, Boulton, Chellaston, Normanton, and Sinfin.

2023–present: Following a local government boundary review which came into effect in May 2023^[2][3], the constituency now comprises the following wards of the City of Derby:

• Abbey (small part); Alvaston North; Alvaston South; Arboretum (nearly all); Blagreaves; Chellaston & Shelton Lock; Darley (small part); Normanton (most); Sinfin & Osmaston.^[4]

Derby city centre has been in this constituency since 1974; from 1950 it had been in Derby North.

The constituency takes in Derby city centre including much of its varied income inner-city, a narrow majority of which used to be local council-built however which is offset by conservation areas including beside Derby Cathedral and Derby Catacombs. The remainder of the seat is generally more affluent suburbs, and much of the engineering industry traditionally associated with the city.

The constituency was created in 1950, when the former two-seat constituency of Derby was split into two single-member seats. Unlike the Derby North seat, this seat has to date been a Labour Party seat.

A notable former MP for the seat was its first incumbent, Philip Noel-Baker of the Labour Party. He served as a Cabinet minister in the post-war Attlee government, and was awarded the Nobel Peace Prize in 1959 for his campaigning for disarmament. He had previously represented the former two-seat constituency of Derby since a by-election in 1936.

The former Cabinet minister Margaret Beckett, who had represented Lincoln (under her maiden name of Margaret Jackson) from 1974 to 1979, has represented Derby South for the Labour Party since 1983. At that election Beckett won the seat with one of the smallest majorities seen of just 421 over the Conservative Party, since which she has achieved only larger majorities than this. The most recent result, in line with other Leave-voting seats, is a reduced majority for Labour, with both the Conservative and Liberal Democrat candidates increasing their vote share, however Beckett still won a majority (51%) of all votes cast, higher than in the elections between 2005 and 2015, suggesting the seat is a relatively safe seat for the Labour Party.

• List of parliamentary constituencies in Derbyshire