Her first Tweet was: "HI TWITTERS. THANK YOU FOR A WARM WELCOME. FEELING REALLY 21st CENTURY," the Chicago Tribune said, noting that most Twitter aficionados disdain those who Tweet in all caps and prefer to be addressed as Tweeple not Twitters.
Actor Ashton Kutcher was seen tutoring Winfrey on how to Twitter on Friday's episode of her chat show.
Kutcher this week became the first Twitter user to attract 1 million followers, with CNN reaching the milestone shortly after, The Tribune said.
"We will be twittering live with @Oprah tomorrow. Gentleman start your search engines. lol," the newspaper quoted Kutcher as saying in a posting Thursday afternoon.