In 2017, on a Wimbledon wildcard, Clarke and Marcus Willis beat the defending doubles champions and second seeds, Nicolas Mahut and Pierre-Hugues Herbert, in the second round, in five sets.

Playing in the Great Britain Under 14 boys team, with Samuel Ferguson, they won the European Winter Cup defeating Sweden in the final.

He trained with Andy Murray before the French Open and travelled with the Great Britain Davis Cup team for their tie against France.

Clarke was awarded a wildcard to the doubles main draw with Marcus Willis, where they reached the third round after upsetting the defending champions and second seeds Nicolas Mahut and Pierre-Hugues Herbert in a five-setter.

[6] Clarke made his ATP main draw debut at the Queen's Club Championships where he was given a wildcard into the singles event, he lost in straight sets to the American fifth seed Sam Querrey.