Rachel Maddow, MSNBC’s highly rated host, has signed a new deal that will keep her at the network for the next several years, according to people familiar with the matter.

The deal ensures that Ms. Maddow—host of “The Rachel Maddow Show” and a linchpin of MSNBC’s prime-time lineup—will remain at Comcast Corp.’s NBCUniversal News Group as it ramps up its video-streaming efforts.

Ms. Maddow, whose show airs weeknights on MSNBC, will continue to host her show on weekdays, some of the people said.

As part of the deal, Ms. Maddow will develop a variety of projects in a new partnership with NBCUniversal, the people said, though the details are still being finalized.

Insider earlier reported on Ms. Maddow’s contract renewal.