The 33-year-old walks away from a professional career that spanned 14 years and 7 clubs.
The 33-year-old former U.S. international made the announcement Friday, in a letter on Toronto FC's website explaining his decision.
"Today, I am announcing my retirement from soccer," Califf wrote. "It is a very emotional day for me. My family has moved around the world to watch me play the sport I love. Now, I get to watch my three kids play the same sport that has given me so much.
"Thanks to my family and friends for their love and support. Also to my teammates, and to my fans, the people who really make playing worth it."
Califf retires as a TFC player after making just four league appearances for the Canadian club. He joined Toronto in Dec. 2012 through the MLS Re-Entry process, and was brought in to be a veteran presence on a rebuilding squad.
He will continue on with TFC as a scout based from his home in California.
“I’m sorry Danny is unable to carry on playing at the level he would like, and totally respect his decision to retire," TFC president and general manager Kevin Payne said. "He’s been a very good player and should be proud of what he’s accomplished.
"I’m very pleased that he will continue to be a part of our organization and assist us in building our team for the future.”
Califf began his pro career with the Los Angeles Galaxy in 2000, where he proceeded to make over 100 league appearances over five seasons. In 2005, he moved on to the San Jose Earthquakes, with whom he won the MLS Supporters Shield and was named to the league's Best XI.
After one season in Northern California, Califf decided to test the European waters and signed on with Aalborg in Denmark. His Danish adventure lasted two seasons with Aalborg and one at Midtylland before Califf returned to MLS in 2010 with the then-expansion Philadelphia Union.
He captained the Union for three years before joining Chivas USA for the 2012 campaign.
In addition to the Supporters Shield with the Earthquakes in 2005, Califf won MLS Cup (2002), Supporters Shield (2002), CONCACAF Champions Cup (2000) and the U.S. Open Cup (2001) with the Galaxy. The defender also helped Aalborg to a Danish Superliga title in the 2007-08 campaign.
At the international level, Califf earned 23 caps for the United States. He was on the squad that won the CONCACAF Gold Cup in 2002, and he also represented the U.S. in the 2003 FIFA Confederations Cup, 2007 Copa America, and 2000 Olympic Games.