In the 2017–18 season after the creation of a under-23 championship, club president Bruno de Carvalho announced the end of Sporting CP B.

President Frederico Varandas decided to refound Sporting CP B in 2019 and the team resumed operations in the 2020–21 Campeonato de Portugal.

[3][4] Sporting B's first season back ended with a best-ever fourth place, under managers Oceano and later José Dominguez.

[6] After the dismissal of Carvalho in August 2018, Sousa Cintra reverted the former's decision, subscribing the reserve team to the new season in the Campeonato de Portugal (Portuguese football's third tier), but he later gave up, with Santa Iria replacing Sporting CP B.

[7][8] In 2019, President Frederico Varandas decided to reestablish Sporting CP B for the next year's Campeonato de Portugal.