The deal carries an average annual value of $2.75 million.
The two parties were slated to have an arbitration hearing on July 29.
The 26-year-old from the Czech Republic had a breakout 2018-19 campaign, making a career-high 42 starts as part of a tandem with Mike Smith. He also posted personal-bests in save percentage (.911) and goals-against average (2.61).
Calgary also signed former Edmonton Oilers netminder Cam Talbot to a one-year, $2.75-million contract on July 1, while the Oilers grabbed Smith in free agency on a one-year, $2-million deal.
The six-foot-three, 206-pound Rittich has compiled a .909 save percentage and 2.70 GAA across three years and 67 games with the Flames.
He previously spent two years with BK Mlada Boleslav in the Czech Extraliga.
July 27, 2019