On the final day of the Aquatics GB Swimming Championships, Oliver raced the 200m Backstroke. Oliver enters the event as the second fastest seed behind Olympic Bronze Medallist from the Tokyo 2020 games Luke Greenbank and ahead of reigning Commonwealth Champion Brodie Williams. 

Oliver went in the second last seeded heat and produced a time of 1:58.89. This time booked himself a middle lane in the final and put him second seed just behind Luke Greenbank and ahead of Jonathon Marshall. 

In the final, Oliver was off to a smooth start turning 5th at the 100m mark. At the 150m mark, Oliver turned in 3rd, over a body length behind Jonathon Marshall and Luke Greenbank. Oliver stormed the field on the way home with the fastest last 50m split to touch in a new personal best time of 1:56.27, just out touching Greenbank by 0.12, to capture his second British title of the week and successfully defending it.