"Roseanne Roseannadanna" was a character created and portrayed by Gilda Radner on Saturday Night Live and later in Radner's live one-woman shows. Her name is likely a reference to 1970s WABC-TV newsreader Rose Ann Scamardella. The character would appear as a commentator during the Weekend Update segments during Jane Curtin's tenure as Weekend Update anchor.

As portrayed by Radner, Roseannadanna was a brash, tactless New Yorker with a thick Brooklyn accent, and her commentary would follow a strict formula. She would read a letter which was almost always from the same person: Richard Feder of Fort Lee, New Jersey (although, on one occasion she read a letter from a "Mrs." Richard Feder). The letter would ask a series of questions, usually about some current social issue, to which Roseannadanna would usually reply, "Mr. Feder, you sure do ask a lot of stupid questions for a guy from New Jersey." or "You belong in New Jersey!" Then she would sometimes make a derogatory comment about New Jersey.

While answering the questions, she would invariably digress, launching into a lengthy anecdote with no relevance whatsoever to the topic at hand. Inevitably, the story would lead into Roseannadanna's going into disgustingly graphic detail about bodily functions or personal hygiene; with these details, she would use a famous celebrity as an example and say that she would ask these celebrities, "What are ya tryin' to do, make me sick?!"

Eventually, Curtin would interrupt, stating, "Roseanne, you're making me sick". Curtin would then ask her what her comments had to do with the question. Roseannadanna's response was, "Well, Jane, it just goes to show you, it's always something." She would then wrap up her comments by sharing a piece of advice passed down from a family member (often her father, but sometimes her "Nana" Roseannadanna; in one episode, she mentioned her aunt Pollyanna Roseannadanna, and in another, her "musically happening cousin, Carlos Santana Roseannadanna").

The character also had a tendency to refer to herself by her full name whenever possible ("Mr. Feder, I know what your talkin'about, because, I, Roseanne Roseannadanna, once had the same thing happen to me.") and often exaggerated her tribulations, saying, "I thought I was gonna die!"

For example, she was talking about eating a hamburger in a restaurant and how she felt something hard in it. And she spit it out and it was white and looked like a toenail. She said, "I thought I was gonna die. I mean, what was a toenail doing in my hamburger?" Then she went to the restroom and on the way to the restroom she saw Princess Lee Radziwill who she described as the "classy lady that no one knows where she's the princess of." But what the Princess didn't know was she had a tiny piece of toilet paper hanging off her shoe, and she was walking around and the toilet paper wouldn't fall off. "I thought I was gonna be sick. So I says to her, 'Hey Princess Lee—what are ya tryin' to do, make me sick?' " So Jane Curtin asked her what this had to do with anything. Roseanne said, "Well it just goes to show you, it's always something, you either got a toenail in your hamburger or toilet paper clinging to your shoe."

In Radner's off-Broadway one-woman show, she included a sketch where Roseanadanna was invited to give the commencement speech at Columbia University. In an apparent attempt to prepare the new graduates for the hard road ahead, she described a job interview she'd had with CBS, in which Walter Cronkite mistakenly thought she'd "passed gas" and consequently kicked her out of his office. The character was later credited as "co-author" of Radner's book Roseanne Roseannadanna's Hey Get Back to Work. In the last year of her life Radner released a memoir of her experience with ovarian cancer entitled It's Always Somethin! in reference to one of Roseannadanna's catchphrases; Radner also recorded the book on audio, imitating Roseannadanna and other of her SNL characters when describing those parts of her life.