Born in the United Kingdom but raised largely in New Zealand, Blomqvist began karting in 2003 and won eight championship titles in New Zealand before moving to Europe in 2009 at the age of fifteen to pursue single-seater racing. He competed in Formula Renault 2.0 Sweden, taking five podiums and one victory, and in the Formula Renault NEZ Championship.
In 2010, Blomqvist won the Formula Renault UK Championship with Fortec Motorsport, becoming the youngest ever champion in the series' history at 16 years of age — breaking a record previously held by Lewis Hamilton. At the 2010 Macau Grand Prix he finished third in the Formula BMW Pacific race with Eurointernational and received the McLaren Autosport BRDC Award.
After joining the McLaren Driver Development Programme in early 2012, Blomqvist pursued European Formula 3 across 2012–2014. Despite a back injury in 2011 that required months of recovery, he returned to post impressive results. Selected by the Red Bull Junior Team for 2013, he finished seventh in the FIA European Formula 3 Championship that year. In 2014, now with Carlin under the Jagonya Ayam banner alongside Antonio Giovinazzi and Sean Gelael, he finished second in the championship — despite carrying engine change penalties.
In February 2015, BMW announced Blomqvist had secured a multi-season DTM drive, replacing Joey Hand after a selection test at Jerez against several rivals including Robin Frijns, Alex Lynn, and Sam Bird. He joined the RBM Team alongside Augusto Farfus.
Blomqvist made an immediate impression in his debut DTM season, becoming the youngest BMW driver to win a race in the series and the second youngest race winner from any manufacturer, taking victory at Oschersleben. He finished fourteenth overall in 2015.
For 2016, he remained with RBM alongside new teammate Maxime Martin. The season was his most consistent DTM campaign, ending in sixth place in the Drivers' Championship — the youngest driver in the top ten of the final standings. In 2017, Blomqvist stayed with BMW in the newly formed Team RBR alongside Timo Glock. After the 2017 season, Blomqvist did not return to the DTM, transitioning to Formula E and endurance racing.
Blomqvist raced in Formula E with the MS&AD Andretti team during the 2017–18 season, making his debut at the Marrakesh ePrix replacing Kamui Kobayashi. His teammate was António Félix da Costa. Though he impressed in his debut, finishing eighth, he was replaced after a handful of races by Stéphane Sarrazin. Blomqvist returned for the final two races of the 2019–20 season with Jaguar as a replacement driver, and then received a full season at NIO 333 in 2020–21. The car was one of the slowest on the grid, and Blomqvist accumulated six points before departing for endurance racing.
The endurance chapter of Blomqvist's career has proved by far the most fruitful. He won the 2018 24 Hours of Spa with BMW Motorsport in a BMW M6 GT3 for Team Walkenhorst Motorsport alongside Philipp Eng and Christian Krognes.
In the 2021 FIA World Endurance Championship, Blomqvist drove for Jota Sport alongside former Carlin teammate Sean Gelael and Stoffel Vandoorne, finishing second in LMP2 class with four podiums across five races, including a class second at the 24 Hours of Le Mans.
Blomqvist joined Meyer Shank Racing in the IMSA SportsCar Championship and won the DPi class Drivers' title in 2022 alongside Oliver Jarvis. He then won the 24 Hours of Daytona in both 2022 and 2023, establishing himself among the leading endurance drivers in North America.
Blomqvist's career arc — from Formula Renault UK's youngest champion to DTM race winner to Daytona double winner — demonstrates rare versatility across open-wheel, tin-top, and prototype machinery. His DTM breakthrough at Oschersleben in 2015, at the age of 21, signalled a talent that ultimately found its fullest expression in endurance racing.