Fox has spent billions of dollars acquiring the TV rights to college football and major-league baseball games as content for cable channels and broadcast TV stations.
Fox News was not part of the new distribution deal, though Comcast says it negotiated new-media rights that allow streaming of Fox News onto non-TV devices to bolster its "TV Everywhere" initiative.
Fox's agreement with the pay-TV distributor - the prior one expired in early January - was announced one day before Comcast is to discuss its fourth-quarter and full-year earnings in a Wednesday conference call with analysts.
The deal covers the cable networks FX, FX Movie Channel, Fuel, Fuel TV, Fox Soccer, National Geographic Channel, Nat Geo Wild, MundoFox, Fox Deportes, and Fox Business Network; 13 Fox TV stations; and Fox regional sports networks in Kansas City, Arkansas and New Mexico.
An additional dozen Fox regional sports networks were not part of the agreement.
Xfinity customers also can download Fox entertainment onto mobile devices under the terms of the agreement, Comcast spokeswoman Jennifer Khoury said.
Comcast has now reached distribution agreements with CBS, the Walt Disney Co. and NBCUniversal.
"This agreement will bring Fox's brands and content to Xfinity TV customers on all platforms, and we are excited to begin this journey with Comcast," said Mike Hopkins, president of distribution for Fox Networks.
Comcast's Khoury said: "This multiplatform agreement includes extensive new media rights, including full current seasons of top Fox shows On Demand."
Contact Bob Fernandez at 215-854-5897 or firstname.lastname@example.org or follow at Twitter @bobfernandez1.