His show, "The O'Reilly Factor," drew just over 3 million viewers Wednesday night. That's up 11 per cent over the same day last year.
The Nielsen ratings company says O'Reilly had his largest audience since last summer among the 25-54 age demographic, the basis of most ad sales for news programming.
The audience among that younger demo was up 64 per cent over last year for O'Reilly, who usually has a decidedly older audience.
Stories over the past week have accused O'Reilly of falsely saying he was reporting from a war zone in the Falklands War and was at the site of the suicide of a friend of John F. Kennedy assassin Lee Harvey Oswald.
O'Reilly has defended his reporting.