Rugby star Warburton and Tottenham Hotspur footballer Bale both attended the Cardiff school, and the pair have been praised for their achievements this week.
"You have to sit down and smile at what's happened," London 24 quotes Whitchurch PE teacher Gwyn Morris as saying.
"It's not often that you have a former pupil who wins not one but two PFA awards, and the British Lions captain within the space of a 48 hour phase. It's special for the school and I am immensely proud. It's phenomenal. We had to pinch ourselves this morning."
Warburton regularly returns to Whitchurch to give coaching lessons to students.