The lights go out in the audience and light up a small stool and a microphone. The crowd members filling the University of Iowa Iowa Memorial Union Main Lounge go quiet. A moment’s pause, then — the comedian they’ve  been waiting for.

Retta takes the stage.

On Saturday, Marietta Sirleaf — known by her stage name Retta — will appear in Iowa City. Many know her as Donna Meagle from the hit NBC show “Parks and Recreation.” Others may know her from “It’s Always Sunny in Philadelphia,” or from her Comedy Central special. For the UI crowd, Retta will perform a standup routine.

Known for her storytelling standup, she centers her routines on her family, friends, and funny situations in which she’s found herself. Contrary to popular belief, Retta said, standup is almost all scripted.

“I do a planned set, and then you just got to hope and pray it works out,” Retta said and laughed. “I mean, I hope it sounds funny.”

She said she has long been interested in comedy, and she has made a name for herself in the comedy scene over the last decade.

“After college, I was working as a chemist in North Carolina, and I’d watch TV and these comedians on sitcoms, and I was like, ‘I can do that,’ ” Retta said. “So I started doing open mikes around the area and then after a year, I moved out to LA.”

Since these early years, Retta has been dubbed one of TV’s Best Scene Stealers by “Entertainment Weekly,” and she has established a popular Twitter personality. She has also built up a comedy résumé that made her a good candidate for the Campus Activities Board’s annual beginning-of-the-year comedian.

Elsie Howe, the comedy director for the board and DI employee, laughs a little before describing the process of booking Retta.

“Last April, I was at the National Association of Campus Activities in Minneapolis and ran into this agent — Kate Edmunds — she works for Joey Edmunds Talent Agency — and she’s like, ‘I think I know someone for your school,’ ” Howe said.

For the board, the process of bringing a comedian to town is somewhat complicated. For the bigger standups, it comes down to booking agents and what works for the university.

“We talk to a lot of agents, and I watch so much standup, like so much standup,” Howe said. “We have to see who will work with our schedule and our budget. After Kate talked to me, we seriously considered Retta. She worked really well for us, so we went from there.”

Comedy has expanded in Iowa City in the last few years. With the inclusion of several improv troupes, open-mike programs, and comedy showcases, UI students and local residents are definitely excited about the coming appearance.

“Some people write, some people do standup, some people do improve — some people do all three,” said Robert Flannigan, a local standup comedian. “I’d definitely like to think there’s an importance to standup. You’re up there alone, so you have to own everything.”

He will host a comedy showcase at the Fairgrounds at 6 p.m. Saturday before going to the show.

Retta has performed on “Parks and Recreation” for six seasons. For the first couple years, she portrayed Donna Meagle as a recurring role in the Parks and Recreation Department in the fictional Pawnee, Indiana. Then in season three, she was promoted to a series regular.

“I definitely prefer acting to standup,” Retta said. “You get to work with people and other actors. They [acting and standup] don’t have many similarities, except you incorporate improv into both. We always do what we call a fun run on set. We can do whatever we want, but still got to get the point of scene across. We don’t have to stick with the lines.”

Retta said the Season 4 episode “Sweet Sixteen” — in which Anne (Rashida Jones) tries to prevent the citizens of Pawnee from wrapping whole mouths around drinking-fountain spouts — is one of her favorites. She also enjoyed Donna’s role in season five’s “Halloween Surprise.”

“I got to live tweet when Chris [“Parks and Recreation” character Chris Traeger] screens this movie for Halloween. That was pretty fun,” Retta said.

She said she is planning on reprising her role as Donna on “Parks and Recreation” for its final season and continuing to perform standup and comedy in general.