Ronald Ulysses Swanson is a fictional character portrayed by Nick Offerman in the political satire sitcom Parks and Recreation. The character was created by Michael Schur and Greg Daniels with inspiration from a real-life Libertarian elected official. Offerman provided creative input, and aspects of his own personality were folded into the character. Despite the creators' intentions, NBC was initially reluctant to cast Offerman in the role, but the network finally agreed, five months later.

Swanson is the director of the Parks and Recreation Department of Pawnee, Indiana, and the immediate superior of the deputy director Leslie Knope (Amy Poehler). He has a deadpan personality and actively works to make the government less effective. He despises interacting with the public and claims to not be interested in the lives of those around him, but he is shown to care for his colleagues and has particularly strong respect for Knope. He secretly performs as a saxophonist named Duke Silver and fronts a band called the Duke Silver Trio.

Offerman's portrayal of Swanson has received widespread critical acclaim. The character developed a cult following and is widely considered the breakout character of the series. He was described by some critics as one of the best characters in a comedy television series in decades, and his platonic relationship with Knope has been compared to that of Mary Richards and Lou Grant in The Mary Tyler Moore Show. For his performance as Swanson, Offerman won the TCA Award for Individual Achievement in Comedy.

Ron Swanson was created by Parks and Recreation creators Greg Daniels and Michael Schur. While researching for the show in Burbank, Schur met a Libertarian elected official who favored as little government interference as possible, becoming an inspiration for some of Swanson's traits. Swanson is also partially inspired by political appointees of former president George W. Bush who were perceived to be opposed to the branch of government they were overseeing.

Nick Offerman had some input into the character's creation, and many aspects of the character were based on the actor's, such as the character's deadpan personality, which Offerman cultivated when he was a lector. Other aspects included his woodworking abilities and experience in stage combat and kabuki. Like Swanson, Offerman played the saxophone, but the writers were not aware of the fact when developing the character. According to Offerman, NBC was initially reluctant to cast him as the character, despite Schur and Daniels' intentions. After the creators refused to find other actors for the role, the network finally acquiesced five months later. Ron became more heavily involved in Parks and Recreation's storylines during the second season, and Offerman largely credited Schur with the development of the character.

Ron's second ex-wife, Tammy, was played by Offerman's wife, actress and comedian Megan Mullally. Ron's hatred towards Tammy was established early in the creation of the character, and it was Schur who conceived the idea of casting Mullally, to which Offerman responded positively.

In the first six seasons of Parks and Recreation, Swanson served as the director of the Pawnee City Department of Parks and Recreation, a role he had for six years when the series began. In the first eleven episodes of the seventh season, in which the show is fast-forwarded to 2017, it is revealed that he had quit his job two years prior and started his own company called the Very Good Building Company. In the last two episodes of the seventh season, which partly takes place in the future, Swanson had resigned from the company, and Knope in turn made him the superintendent of Pawnee National Park.

Offerman appeared in all 125 episodes of the show except for "Beauty Pageant". He reprised his role in a 2020 special featuring the original cast, titled A Parks and Recreation Special, which served as a fundraiser for Feeding America's COVID-19 Response Fund.