The 40-year-old - a free agent since leaving Fulham last month - has agreed a one-year contract to provide cover for Czech Republic international Cech at Stamford Bridge.
Cech has been a near ever-present for the Blues in his nine seasons in London, with Hilario and Ross Turnbull among the several deputies unable to displace him.
But Schwarzer still harbours ambitions of representing Australia at next year's World Cup and knows he will need game time to ensure his spot on the plane to Brazil.
The former Middlesbrough keeper told Sky Sports News: "Petr is number one - that goes without saying.
"For me what was important was that I could come to a club the size of Chelsea and really try and push myself as much as possible.
"If I can help Petr Cech improve as a goalkeeper and help myself improve as a goalkeeper then we can learn a lot from each other and I'd be delighted with that.
"There's a lot of games throughout the season and I know that if I'm pushing as hard as I can do then there'll be opportunities along the way."
Schwarzer revealed returning Blues boss Jose Mourinho had helped persuade him to join "one of the best clubs in the country" after speaking to the Portuguese about his future options.
He added: "I've spoken to the manager at Chelsea and it was very easy to make the decision that Chelsea was the right club for me."