The Blues captain is back at the heart of Chelsea's defence, having found himself anything but first choice under Rafa Benitez last season.
Chelsea have started the season well and are undefeated after three games, and Terry says their form is all down to Mourinho.
"We are looking fit and very much together - and Jose brings that," Terry told the Daily Mirror ahead of Saturday evening's clash at Everton.
"It is us against everyone else and I think that is what made us when he was here before and we are very much in the same mould again."
Terry skippered Chelsea to two Premier League titles during Mourinho's first spell in charge in west London, and he believes the Portuguese manager is more than capable of inspiring similar success in his second stint at the helm.
"His man-management is excellent and he makes people want to play for him," added Terry. "He has it spot on.
"If there was a managerial manual, he would tick every box. We are delighted to have him back.
"He has come home and all the players feel the same.
"Hopefully what we know about Jose and what Jose knows about the Premier League will make the difference in the title race."