In February 2016, Aitken was one of four drivers confirmed to join the young driver program of Renault F1. In September 2017, Aitken sampled Formula One machinery for the first time, testing the Lotus E20 at Jerez. In February 2018, Aitken was appointed as third and reserve driver for Renault. Aitken continued as test driver for Renault in 2019, taking part in the young drivers' test at the Circuit de Barcelona-Catalunya.