A Wikipedian in residence or Wikimedian in residence (WiR) is a Wikipedia editor, a Wikipedian (or Wikimedian), who accepts a placement with an institution, typically an art gallery, library, archive, museum, cultural institution, learned society, or institute of higher education (such as a university) to facilitate Wikipedia entries related to that institution's mission, encourage and assist it to release material under open licenses, and to develop the relationship between the host institution and the Wikimedia community. A Wikipedian in residence generally helps to coordinate Wikipedia-related outreach events between the GLAM ("galleries, libraries, archives, and museums") and the general public such as editathons.

Institutions that have hosted a Wikipedian in residence include large institutions like the National Library of Wales, the University of Edinburgh, the British Museum, the National Institute for Occupational Safety and Health, the British Library, the Smithsonian Institution, the Royal Society of Chemistry, UC Berkeley, Columbia University, City University of New York, the University of Toronto, the National Library of Norway, and the Federal Archives of Switzerland and smaller venues like the Derby Museum and Art Gallery and The New Art Gallery Walsall in the UK; the Palace of Versailles in France; the Museu Picasso and the Museu Nacional d'Art de Catalunya in Catalonia; the National Book Council and the Times of Malta in Malta; and the Children's Museum of Indianapolis, Consumer Reports, the Gerald R. Ford Presidential Library, and the National Archives and Records Administration in the United States.

The primary role of the Wikipedian in Residence (WiR) is often to serve as a liaison between the host institution and the Wikimedia community by assisting with events and training that support the missions of both organisations. Typical training duties include arranging and/or leading training events and editathons and providing explanations to other staff and members of the public about policies and practices, such as policies about conflict of interest. Editing activities may include making contributions to articles relevant to the institution's materials and mission, such as articles about significant cultural objects in an organization's collection, or articles in a specific field of knowledge.

Another common form of collaboration involves digital collections. A WiR can provide training on digitization and help upload media (with any existing metadata) to Wikimedia Commons. Wikimedia volunteers can then translate, extend, and reverify metadata, categorizing media and manually transcribing and structuring scanned documents on Wikisource. The description and categorization functions on Wikimedia Commons are sometimes preferred to those of commercial websites and the institution's catalogue software. Media added to Commons are used in Wikipedia, both by the WiRs and by volunteer editors.

A third form of collaboration involves datasets and APIs in their own right; for instance, the Wikimedia Foundation funded a Wikipedian in Residence at OCLC to integrate the OCLC's WorldCat Search API into Wikipedia's citation autocompletion tools, making adding references faster for Wikipedia editors. WiRs have also helped integrate ORCID metadata and rights statement data. Some WiRs work for only a short period, as little as a few weeks, while others have permanent positions. In the case of short-term positions, it is important that the work to be done be well-planned in advance.

While Wikipedia discourages direct paid compensation for article editing and prohibits undisclosed advocacy, Wikipedians in residence are permitted to be compensated for work on-wiki – either by offering credit, stipend, or salary – through their sponsoring institutions provided that they adhere to strict guidelines against engaging in public relations or marketing for their institution.^{[citation needed]}

In 2010, Australian Liam Wyatt became the first Wikipedian in residence when he volunteered at the British Museum for a period of five weeks. He noted the need for Wikipedia to strengthen partnerships with museums to create the most up-to-date and accurate information, saying "we are doing the same thing for the same reason, for the same people, in the same medium. Let's do it together." The Children's Museum of Indianapolis became involved with the program after Wikipedian Lori Phillips volunteered for a GLAM event in 2010, becoming the second Wikipedian in residence. The third, Benoît Evellin, spent six months at the Palace of Versailles in Versailles, France. The Museu Picasso in Barcelona, Spain and the Derby Museum and Art Gallery in Derby, England were also early adopters of the idea.

In 2010, the Smithsonian Institution expressed interest in the idea, which led to the hiring of Sarah Stierch in July as Wikipedian in residence. The following year, the National Archives and Records Administration followed suit and hired Dominic McDevitt-Parks, a student from Simmons College, who was pursuing a master's degree in history and archives management, to work at its Archives II location in College Park, Maryland. McDevitt-Parks had been editing Wikipedia since 2004 and was hired for this position by David Ferriero.