The Chelsea legend opted to drop down a division to help with the Villans' promotion push after bringing an end to his two decade-long association with the Blues.
Grealish has credited Terry's arrival at Villa Park for his return to peak form, having played a direct part in goals in each of Villa's last three matches, including an assist for Lewis Grabban's winner against Leeds United on Friday night.
"Me and him are always in the training ground chatting and doing whatever. I do get on so well with him," he is quoted as saying by The Mirror. "Everyone knows how much of a good player he has been and what he has done in the game. When he first signed I had to pinch myself.
"He is so professional in everything he does that rubs off on us young players. I will be thinking: 'do I need to be doing that' when he is doing it because look where he has got.
"Things like ice baths, massages and not going home after training straight away. He is always the last person there eating properly and doing everything right."
Grealish, who came through Villa's youth ranks, recently admitted that he 'needs' to be playing Premier League football.