Ms Ward said she was ‘humbled’ as she polled 181,040 for a majority of 51,708.
Ben Bradley, current Mansfield MP and Nottinghamshire Council leader, came second for the Conservatives with 129,332, while Frank Adlington-Stringer was third for the Greens with 50,660.
Ms Ward will now head up the new East Midlands Combined County Authority, which was created after a devolution deal was signed by the four upper tier councils of Derbyshire County Council, Nottinghamshire County Council, Derby City Council and Nottingham City Council in November 2022.
She will be given powers, currently held by Westminster, to invest over the long-term in priorities like transport, skills, housing and regeneration and net zero.
The devolution deal also guaranteed a funding stream of £1.14bn, spread over a 30-year period.
The result has reflected a tough night for the Conservatives in the local elections and on a national level after they lost the Blackpool South by-election, although the party did defy the odds to hold on to the Tees Valley mayoral seat.
Full result:
Claire Ward (Lab) – 181,040
Ben Bradley (Con) – 129,332
Frank Adlington-Stringer (Green) – 50,660
Alan Graves (Reform UK) – 49,201
Matt Relf (Ind) – 23,359
Helen Tamblyn-Saville (Lib Dem) – 15,970