Many details about the riot and attempts to overturn the 2020 election were made public for the first time during the January 6 committee hearing.
NBC had 3.5 million viewers, followed by CBS with 3.3 million.
MSNBC drew 4.1 million viewers while CNN drew 2.6 million.
While Fox News did not show testimony, it ran a nightly lineup of shows hosted by Tucker Carlson and Sean Hannity, who have been critical of the committee's investigation.
3 million people watched Fox News during the 8 pm to 10 pm time period. The hearing took place during the daytime.
According to a New York Times review of data, most people who watched the hearing stayed on top of it.
The three NBA Finals games have been watched by more than one million people. The games had an average of less than 12 million viewers.
The committee had promised new information about the attack on the Capitol and Donald Trump's connection to the rioters. Several members of Congress asked for pardons after the rioting, as well as the fact that Trump told staffers he had no problem with calls to lynch former Vice President Mike Pence.
Riot defendants say Trump asked them to storm the capitol.