Oliver started karting like many other drivers, starting at the age of seven. From there he won many championships across Britain: 1st in Kartmasters British Grand Prix, Corner Cadet category; Super 1 National Comer Cadet Championship in 2003 and 2004; Super 1 National JICA Championship; CIK-FIA World Cup KF2 category; CIK-FIA World Cup in Super KF & KF1. This was followed by a multitude of 2nd and 3rds in Super 1 National Comer Cadet Championship, Super 1 National JICA Championship, British Championship ICA Junior, Kartmasters British Grand Prix ICA Junior, Monaco Kart Cup in the ICA Junior category, Super 1 National JICA Championship, British Open Championship ICA Junior and WSK International Series in the KF2 category.
Rowland moved up to single seaters in the Formula Renault UK Winter series in 2010 driving with CRS Racing. Out of the 6 races, he managed to claim a win in round 3’s Pembrey, Carmarthenshire. With 95 points in the season, he finished 7th in the standings.
For 2011, he raced in the main Formula Renault UK series with Fortec Motorsport, racing for the 20 races. Here, he managed to claim 4 wins and 13 podiums, amassing 475 points. This put him 2nd into the standings behind Briton Alex Lynn. Also during this year, he competed in the renamed Formula Renault UK Finals Series, competing in the 6 rounds. Rowland was on the podium for every race and had 4 wins meaning he finished the season as the champion.
Oliver stepped up a Formula Renault category, now racing in Eurocup 2.0 again with Fortec Motorsport. His consistent performance with 109 points left him in 3rd, behind Stoffel Vandoorne and Daniil Kvyat.
Rowland stayed in Formula Renault 2.0, this time racing in the main series and the Northern European Cup. In the main series, he finished 2nd with 3 wins and 8 podiums behind French Pierre Gasly. In comparison, Oliver competed in NEC and despite only racing for 8 races (4 rounds), he managed to finish on the podium for all 8 and won 4. He ended up 4th in the standings with 208 points, sitting behind Matt Parry, Jack Aitken and Dennis Olsen. For the one off race in Pau, Oliver drove with Manor MP Motorsport. In the qualifying race, he finished in 3rd and for the main race, he finished in 4th.
In 2014, Rowland moved up to Formula Renault 3.5, racing with Fortec Motorsports with Russian Sergey Sirotkin. Out of the 17 races, he won 2 and was on the podium 7 times. With 181 points under his name, he finished in 4th behind Roberto Merhi.
For the following season, he remained in Formula Renault 3.5 Series, this time partnered with Jazeman Jaafar. With 8 wins under his name with 13 podiums out of the 17 races, he finished 1st in the standings ahead of Matthieu Vaxivière. Also alongside his Formula Renault races, he joined in 8 races of GP2 (where he was unclassified for one due to a 2 lap race), 4 with MP motorsport and 4 with Status Grand Prix. He ended up in 21st with 3 points behind André Negrão.
Oliver made his full GP2 debut with MP Motorsport in the 2016 season, driving with Daniël de Jong and had backing from Renault. With 4 podiums, he claimed 107 points which entitled him to the position of 9th behind Luca Ghiotto and ahead of Artem Markelov.
When GP2 had a name change to Formula 2, Rowland continued in Formula 2, though this time with DAMS. In the 22 races, he won twice, once in Monaco and the other in Hungary. With 191 points, Oliver finished 3rd in the standings with 19 points behind 2nd place finisher, Artem Markelov.
2018 is where Rowland started endurance. In the Blancpain GT Endurance series, he raced in the 3 hours of Silverstone and 3 hours of Barcelona. In Silverstone, he finished in 38th and in Barcelona he finished in 7th. This meant he had 6 points thus finishing in 41st. For Mercedes-AMG, Rowland competed in the Intercontinental GT Challenge within the Suzuka 10 hours round. He finished in 7th place, earning 6 points, finishing 22nd.
Besides Formula E, he also raced in FIA World Endurance with CEFC TRSM Racing in 6 hours of Spa and 24 hours of Le Mans. His team did not start the Spa race and in Le Mans, the car did not finish due to electrical problems within the car.
Rowland initially made his Formula E debut with Mahindra Racing, covering for Nick Heidfeld in the Punta del Este ePrix. In his first race, he finished in 13th place behind Oliver Turvey.
Oliver made his comeback to Formula E after being hired to cover for Sébastien Buemi in the 2017 Mexico city ePrix with Renault e.Dams, though not actually racing.
Rowland started to race again in Formula E with Nissan e.Dams after Alexander Albon moved to Toro Rosso, this time partnering Sébastien Buemi. He claimed his first pole and podium in Sanya ePrix. For the season, he finished in 10th for his full debut season, finishing behind Sam Bird.