In 2019, Gourley reached the final of his specialist event in front of the home crowd at the European Indoor Championships in Glasgow but was unable to compete in it due an illness.[5]
On 25 February 2023, the 28-year-old broke Josh Kerr's British indoor 1500 m record with a time of 3:32.48 for a win at the World Indoor Tour Final in Birmingham, replacing him at No.8 on the respective world all-time list. Gourley's success secured him also overall 1500 m World Indoor Tour victory, after his mile win in Boston, MA and runner-up mile finish in New York, NY (with a European indoor record over the distance) earlier that month.[6][7] In March, he claimed the silver medal in his signature event at the European Indoor Championships in Istanbul behind only Jakob Ingebrigtsen, 3:34.23 to 3:33.95.[8] It was Gourley's greatest sports achievement up to that point.
Later that year in May, Gourley opened his outdoor season with a 5000m personal best of 13:16.[9]