Conte led Chelsea to the Premier League title in his first season in charge and will lift the trophy after the match at home to Sunderland on Sunday.
The Italian has two years remaining on his contract and the club will offer him an extension with an increase on his £6.5million-a‑year salary.
However, speculation continues over a return to Serie A with Inter Milan prepared to pay Conte £250,000 a week.
Chelsea are also having to fend off Real Madrid’s bid to buy Hazard and have told the Belgian he will be the focal point of the team for years to come as part of their pitch over a new deal.
Asked if agreeing terms with Conte was just as crucial as Hazard’s negotiations, Cahill told Standard Sport: “Yes, of course it’s important. The powers that be will sort it out.
“Would I like him to stay? The answer is yes, 100 per cent, just like I want all of our players to stay. But the nature of football is that sometimes people stay, people go.
“It’s important we keep the freshness about this team next season, we keep the competition, we keep the goals, keep everything in place to have a successful year.
“Having the same manager in place is fantastic and competition for places everywhere, plus a few additions, that’s always healthy.
“I don’t know why he [Conte] wouldn’t be happy. If you saw him at West Brom [when Chelsea clinched the title], you could see that after just winning the League in his first season. But I can’t speak about people’s personal situations and decisions.”
Conte is the sixth different coach Cahill has worked for during five years at Chelsea.
“I have played under a lot of managers here but it’s the nature of football,” said Cahill. “I can’t speak highly enough of Antonio, he’s been absolutely superb. The way he’s got us playing, how well drilled we are, how organised we are and the football we’ve played — it’s been a breath of fresh air.
“It’s not just him or his staff, it’s everyone you don’t see. It’s been a key to the season — collectively we have been so tight as a group. Even the players who haven’t been playing as much, we have all been together. We have worked hard for this moment.
“But I have thoroughly enjoyed working under him and collectively as a group we have achieved something fantastic.”