The May 25 finale of "The Oprah Winfrey Show" drew 16.4 million viewers, making the episode the show's most-watched episode in more than 18 years, since the February 1993 airing of its "Why I Love Older Women" episode, which was seen by 17.3 million viewers.
Nielson said the audience for the surprise farewell episode that aired May 23 drew 12.3 million viewers, and the second part of that event attracted 13 million viewers the next day.
"The Oprah Winfrey Show" averaged 8.2 million viewers during May.
The Associated Press contributed to this report.
