Born in Munich, Engel grew up in Monte Carlo, went to school there together with Nico Rosberg and came into contact with the motorsport scene at an early age through his father Keke. In 2001, at the age of 15, Engel competed in his first car race in the Formula BMW Junior Cup and finished the season in third place with three victories. In 2007, he also secured the runner-up spot in the fiercely contested British Formula 3 Championship with three victories.
in 2008, Engel joined the German Touring Car Masters and drove a Junge Sterne AMG Mercedes C-Class DTM from the previous year for Team Mücke Motorsport, with which he achieved a ninth-place finish at the Norisring as his best result. Engel remained with Mücke Motorsport until the end of the 2011 season, finishing 12th, 15th and 13th in the respective final driver standings for those three years.
From 2012, Maro Engel turned his attention to GT and touring car racing, including a stint in the International V8 Supercars Championship in Australia in a Mercedes-Benz driven by the Erebus Motorsport team. In 2015, the Munich native decided the GT World Cup in Macau in his favour and won the prestigious race in a Mercedes-Benz SLS GT3. In May 2016, he and his team-mates Metzger, Christodoulou and Schneider won the traditional 24-hour race at the Nürburgring.
Engel then became involved in the up-and-coming Formula E and competed for the Venturi team in the 2016/17 season. While he achieved his best result here with fifth place at the Monaco ePrix, he was surprisingly able to claim his first victory in Moscow in the parallel 2017 DTM season, which he once again contested for Mercedes-Benz.
After just one season, however, Engel left the DTM stage again to devote more time to GT racing and Formula E in the future. He achieved this with a victory in the 10 Hours of Suzuka and second place in the FIA GT World Cup held in Macau – both in a Mercedes-AMG GT3 of the Gruppe M Racing team. Equally impressive were his second place as at the 24-hour race at the Nürburgring and his win in the Blancpain GT Series Endurance Cup, both in a Mercedes-AMG GT3 of Team Black Falcon. Engel's last Formula E season for the Venturi team for the time being was less successful, ending in 12th place overall.
From 2019, the Munich native concentrated fully on continuing his career in GT racing, where he took third place in the ADAC GT Masters in 2020 and 2021. On 23 October 2022, he set a new record for road-legal production cars on the Nürburgring Nordschleife with a time of 6 minutes and 35.183 seconds in a Mercedes-AMG ONE. Following the change in regulations, which stipulates GT3-regulated cars for the DTM from 2021 onwards, Engel started driving in the DTM again in the 2022 season: in a Mercedes-AMG GT3 of the GruppeM Racing team, he finished in 12th place and switched to Team Landgraf for the 2023 season. In both years, he was also involved in the 12 Hours of Sebring, which he contested with a Mercedes-AMG GT E3 Evo of the Weather Tech Racing team. In 2022, he finished 18th with his team-mates Jules Gounon and Cooper MacNeil, in 2023 16th with Gounon and Daniel Juncadella.