Question: Who plays "Sweet Dee" Reynolds on the Rob McElhenney created comedy? 

Context paragraphs:
Reynolds and Branson: Reynolds & Branson Leeds was a business based at 13 Briggate and 14 Commercial Street in Leeds, England.  The business lasted from 1816 to 1972.  Edward Matterson managed the company in 1822, and William West F.R.S. took over the in 1833.  The National Archives Records about the company include a day book, sales ledger, and prescription books.  The records were created by Reynolds & Branson Ltd.  Reynolds & Branson was registered in July 1898 as a limited corporation with a capital of £34,000 in shares of £10 each by Messrs. R. Reynolds, F. W. Branson.  No remuneration was given to Mr. R. Reynolds, but a £700 per annum was given to each of the others.  In 1890, Richard Reynold's son, Richard Freshfield (Fred) Reynolds was made a partner.

Living Loaded: Living Loaded is an American comedy television pilot written by Rob McElhenney and Rob Rosell, based on Dan Dunn's novel of the same name.  The pilot was commissioned by Fox and was slated to air during the 2012–13 season, but it was not picked up as a series.  The cast includes Donald Sutherland, Mike Vogel, and McElhenney.

Please Stay (Burt Bacharach song): "Please Stay" (also known as "(Don't Go) Please Stay") is an early hit of The Drifters featuring the new lead singer Rudy Lewis, who replaced Ben E. King.  It is one of songwriter Burt Bacharach's early pop hits, featuring Dionne Warwick's sister Dee Dee Warwick and Doris Troy on background vocals.  This song, along with "Some Kind of Wonderful" and "Sweets for My Sweet", were recorded in the same session.  The musicians who backed the Drifters on this record include George Barnes and Allan Hanlon on guitar, Abie Baker on bass, Bobby Rosengarden and Ray Kessler on percussion and Ed Shaughnessy and Gary Chester on drums.

Rob McElhenney: Robert Dale "Rob" McElhenney (born April 14, 1977) is an American actor, director, producer, and screenwriter.  He is best known for playing Mac on the FX/FXX comedy series "It's Always Sunny in Philadelphia".  He is also one of the developers, executive producers, and the creator of the show, which has provided him with writing and directing credits on various episodes.

Kaitlin Olson: Kaitlin Willow Olson (born August 18, 1975) is an American actress and comedian.  She began her career in the Groundlings, an improvisational group in Los Angeles, California, and had minor roles in several television series before being cast as Deandra "Sweet Dee" Reynolds on the FX black comedy series "It's Always Sunny in Philadelphia" in 2005.

The Sweet Inspirations: The Sweet Inspirations were an American R&B girl group founded by Emily "Cissy" Houston (née Drinkard), mother of Whitney Houston, and sister of Lee Warrick (herself the mother of well-known sisters Dee Dee and Dionne Warwick).  Houston and Warwick were members of The Drinkard Singers, a family group that had the distinction of recording the first Gospel album to appear on a major label—a live recording from The Newport Jazz Festival in 1959.  The line-up included Judy Guions (who later became Judy Clay), Marie Epps, Larry Drinkard, Nicholas Drinkard, Ann Moss, Lee and Emily.

It's Always Sunny in Philadelphia: It's Always Sunny in Philadelphia is an American television black comedy sitcom that premiered on FX on August 4, 2005.  It moved to FXX beginning with the ninth season, and has remained there since.  It was created by Rob McElhenney, who developed it with Glenn Howerton.  It is executive produced and primarily written by McElhenney, Howerton, and Charlie Day, all of whom star alongside Kaitlin Olson and Danny DeVito.  The series follows the exploits of "The Gang", a group of debauched self-centered friends who run the Irish bar Paddy's Pub in South Philadelphia.

Adam Reynolds: Adam Reynolds (born 10 July 1990) is an Australian professional rugby league footballer who currently plays for the South Sydney Rabbitohs of the National Rugby League.  Reynolds primarily plays at halfback and is a City New South Wales, Prime Minister's XIII, NRL All Stars and World All Stars representative.  Reynolds played in the Rabbitohs' 2014 NRL Premiership winning team.

Turn Around (Dick and Dee Dee song): "Turn Around" is a song written by Malvina Reynolds, Alan Greene, and Harry Belafonte and made popular by Dick and Dee Dee.  It reached #15 on the adult contemporary chart and #27 on the "Billboard" chart in 1963.  The song was also released in the United Kingdom as a single, but it did not chart.  The song was featured on their 1964 album, "Turn Around".

Boldly Going Nowhere: Boldly Going Nowhere was a proposed American television show for Fox.  Rob McElhenney, Glenn Howerton, and Charlie Day, the producers and stars of "It's Always Sunny in Philadelphia", created the show along with their "Always Sunny" writers' assistant Adam Stein.  While they did not plan to star in the show, they were the executive producers.

Supporting paragraphs: It's Always Sunny in Philadelphia Kaitlin Olson
Answer: Kaitlin Olson