In 1945 he went to Alf Gover's Cricket School for three weeks and his father enrolled him at Tonbridge School where he could qualify for Kent, Gover telling the Tonbridge coach Ewart Astill that Cowdrey should join the First XI immediately, a rarity for first year pupils. In the team trial match he was 4 years younger than the other boys, but took 17 wickets with his leg spin and became an established part of the team. Still only 13 in July 1946 he became the youngest player to play at Lord's, for Tonbridge against Clifton, making 75 and 44 and taking 3/58 and 5/33 to win the match by two runs. Tonbridge later established the Cowdrey Scholarships for sporting excellence in his memory.