Miguel is the only Portuguese rider currently competing in the premier class.
In 2011, Miguel began his professional career racing in the 125cc championship. His best result that season was a seventh place in Estoril. He achieved six top 10 finishes throughout the year but was unable to take part in the last races of that year due to team issues.

In 2012, Miguel signed with the Estrella Galicia 0.0 team in Moto3, competing alongside Alex Rins. That season ended for the Portuguese rider with an 8th place in the world championship after achieving two podiums, a second place in Australia, and a third place in Catalonia.

In 2015, with the Red Bull KTM Ajo team, Miguel achieved his first win in Moto3, also becoming the first Portuguese rider ever to do so in the history of the championship. That year was meteoric for Miguel, who secured additional wins in Assen, Aragón, Australia, Malaysia, and Valencia, three second places (Spain, San Marino, and Japan), and a pole position in Argentina. He finished the world championship in second place, just 6 points behind the champion.

2016 marked a year of transition for Miguel. He stepped up to Moto2 with the Leopard Racing team. His top result that season was an eighth place at the Catalan GP.

In 2019, Miguel signed with the MotoGP team Red Bull KTM Tech 3, KTM’s satellite team. He managed to finish within the scoring positions in 9 out of the 16 races he competed in, with his best result of the season being an eighth place in Austria, where he was also the highest-placed KTM rider. He suffered a shoulder injury in a crash with teammate Johann Zarco at the British GP, which worsened after a fall during free practice sessions at the Australian GP. Oliveira did not compete in the Australian GP, ending the season right there.

In 2022, Miguel reconnects with Estrella Galicia 0.0. The brand renews its sponsorship by fostering a close collaborative relationship.

In 2023, the Portuguese rider switches teams, joining Trackhouse Racing, where he continues to race currently.