Election joy for Doreen.
Council leader Councillor George Dunning described the result as a vote of confidence in Labour's running of the authority.
The by-election was caused by Councillor Peter Scott retiring from the council.
Doreen Rudland had a majority of more than 200 over the second placed candidate, Barry Hunt, who stood as an independent.
She said: "It was a great campaign, based around the issues that matter to local people, and on Labour's ability to best represent them. I look forward to working with local people and colleagues on the council, and elsewhere, to help move Brotton forward."
Cllr Dunning said: "This was a tremendous result and a tremendous vote of confidence in Labour's performance in running the council since 2007."
Middlesbrough South and East Cleveland MP Tom Blenkinsop said: "Congratulations to Doreen and the Labour team. This was the first electoral test in the borough since the General Election. The ground is clearly shifting away from the Con-Dem coalition, as people begin to see the reality of their policies."
Result: Doreen Rudland, Lab, 565; Barry Hunt, Ind, 351; Valerie Miller, Lib Dem, 315; Don Agar, Con, 220; Michael George, BNP, 33. Turn-out 27.8%
VICTORY: Labour's new councillor Doreen Rudland