The final presidential debate on Thursday drew just under 63 million viewers, according to Nielsen.
The total fell short of the 73.1 million viewers who tuned in the first time President Trump and former VP Joe Biden squared off.
The final debate drew a household rating of 20.4, down from 23.7 for the first debate.
Four years ago, the final debate between former Secretary of State Hillary Clinton and Trump drew 84 million viewers.
Nielsen's figures for 2020 are based on live coverage for 15 networks and includes viewers streaming on connected TVs.
Fox News Channel had the biggest audience with 14.8 million viewers. Among the other big networks, ABC had 10.8 million viewers, NBC had 10.2 million, CNN had 7.2 million, MSNBC had 6.7 million and CBS had 5.5 million.
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