The 2017 season saw Olli graduate to single seater racing, as he took on the British F4 Championship. Racing with TRS Arden, alongside competing in the Challenge Cup.
Despite having to wait on the sidelines until Round 5, due to not hitting the minimum age until his 16th birthday. Olli arrived at Croft confident after showing strong pace over testing in the winter months, he immediately impressed, mounting the challenge to consistently place within the top-10.
Making his ADAC F4 debut alongside his British F4 Campaign in 2017, despite missing the first two rounds, Olli finished the season in 10th place.
Whilst making a guest appearance in Italian F4 made him illegible for points, he gained valuable experience to take forward ahead of a full season dual campaign in the 2018 season.
Fresh off the back of his strong showing in Europe, Olli put together a strong winter campaign in the UAE Formula 4 series, where he took three wins and four podiums.