Samaia began his racing career in karting in 2012, competing the Florida Winter Tour - Rotax Junior championship. His only season in the championship resulted in Samaia finishing 47th out of 63 competitors. The championship was won by Oliver Askew and had American/Ecuadoran former Formula 2 driver, Juan Manuel Correa also competing, finishing 6th.
Junior Formulas in Brazil
In 2013, Samaia competed in 2 of the 16 races in the Fórmula Junior Brazil championship for Satti Racing Team, gaining 10 points and finishing 16th. For 2015, he switched to the Formula 3 Brazil Light series racing for Cesário. He scored thirteen podiums in sixteen races, including six wins and took the championship title with 171 points, thirty points ahead of 2nd place Matheus Muniz. Sticking with Cesário, Samaia jumped up to Formula 3 Brazil for the 2016 season. He finished 2nd in the first round of the season at Velopark, behind Carlos Cunha Filho. Samaia didn't win his first race until the 1st race at the Autódromo José Carlos Pace Circuit in the forth round of the season, he would go on to win two more races meaning he finished the season with three wins and ten podiums. Samaia finished 2nd with 140 points, sixty-five points behind eventual champion Matheus Iorio. In 2017 Samaia dominated the Formula 3 A Brasil championship, winning all but three of the sixteen races finishing fifth, eighth and second respectively in the races that he didn't win. This ultimately lead to him winning the championship by 87 points.
Samaia made his début in the Euroformula Open Championship in 2017 with Carlin at the fifth round in Silverstone where he finished 14th. Samaia would continue to race for the remaining races where he would finish the season in seventeenth with seven points behind fellow Brazilian Christian Hahn. In 2018 Samaia made the switch to the Italian team RP Motorsport. His highest finish was his only podium when he finished third at the first race of the third round in Belgium. He ended the season 6th with 94 points. Teammate, fellow compatriot and 2020 Formula 2 competitor Felipe Drugovich won the championship with 405 points. For 2019, Samaia switched to Spanish outfit Teo Martín Motorsport where he would race in the first four rounds. He achieved one podium at Le Castellet in the second race of the season which helped him to a sixteenth-place finish.
On 17 February 2020, Campos announced that Samaia would race for them after a successful post season test in Abu Dhabi in. His teammate was also announced on the same day to be the Brit Jack Aitken
