Maguire was strongly linked with a move to Manchester United before the summer transfer window closed on Thursday.
United are said to be considering revisiting their interest in the 25-year-old when the winter window opens in early 2019, but Chilwell has insisted that Maguire will remain at Leicester for the entirety of the 2018-19 campaign.
Both players were in action on Friday night as Leicester opened their season with a 2-1 defeat to United at Old Trafford, and Chilwell also paid tribute to his teammate's performance.
"It is very good to have Harry back. We all know what Harry is capable of, we all know how good he is. He could have come here today (Friday) and his head could have been all over the place, but he did brilliantly," ESPN quotes Chilwell as saying.
"He is a Leicester player, he wants to play for Leicester. He has made that clear to all of us. He is going to be here for the whole season. He is going to be good for us. We saw that again tonight (Friday), how good a player he is. We are all happy that he has stayed."
Maguire has not missed a Premier League match for Leicester since joining the Foxes from Hull City in June 2017.