The Algerian joined City in 2018 after winning the Premier League title and reaching the UEFA Champions League quarter-finals during his time with the Foxes.
"It always feels special for me when I go back there," he said.
"I have spent four and a half years winning the league and playing in the Champions League with City and these amazing people at the club.
"It is always good to be back there. I am happy to be back there, playing in this stadium, so it will be good."
A major weapon in City's hunt for trophies this season is Erling Haaland.
The Norwegian has scored 22 goals in 16 appearances since joining the Club in the summer from a central position but Mahrez insists the No.9's arrival hasn't altered our style.
“I don't think we have changed a lot," he stated.
"Obviously, Erling is a different kind of striker to what we have had in the past. Sometimes we can play a bit more direct with him because he is big and strong.
"Otherwise, we are playing the same that we always did. The only thing that surprised me is the amount of goals he scored. I wasn't expecting this! He has scored a lot of goals already. He is a big presence in the box and a very good player for us."