Charles Ritchie joined the National Gallery in 1980 after receiving his MFA in painting from Carnegie Mellon University. In 1984 he shifted from the Education Department to research on the Gallery’s Index of American Design. His curatorial role expanded in 1988 to include all American and modern prints and drawings.

Ritchie curated in-house and loan exhibitions of watercolor renderings from the Index of American Design (1984–1985). He assisted with the exhibition and catalog The 1980s: Prints from the Collection of Joshua P. Smith (1989) and wrote entries for the exhibition catalog Art for the Nation: Gifts in Honor of the Fiftieth Anniversary of the National Gallery of Art (1991). Ritchie was exhibition curator and authored a catalog for Gemini G.E.L.: Recent Prints and Sculpture (1994). The following year he penned an essay on Frank Stella for the exhibition catalog The Robert and Jane Meyerhoff Collection: 1945 to 1995. Ritchie contributed to the exhibition catalog Art for the Nation: Collecting for a New Century (1999). He organized the exhibition Max Weber’s Modern Vision: Selections from the Holdings of the National Gallery of Art and Related Collections, authoring the companion brochure (2000). He co-wrote, organized, and supervised the launch of the Gemini G.E.L.: Online Catalogue Raisonné, and organized a companion exhibition, Best Impressions: 35 Years of Prints and Sculpture from Gemini G.E.L. (2001). Ritchie was responsible for the exhibition Let the World In: Prints by Robert Rauschenberg from the National Gallery of Art and Related Collections, and authored its exhibition brochure (2007). The Gothic Spirit of John Taylor Arms exhibition was also organized by Ritchie (2011), and he assembled the show Ellsworth Kelly: Colored Paper Images (2012). He co-curated with associate curator Carlotta Owens Modern American Prints and Drawings from the Kainen Collection (2014). Additionally, Ritchie contributed to the exhibition catalog for Three Centuries of American Prints from the National Gallery of Art (2016).

Ritchie has written and lectured on numerous topics related to American art of the 20th and 21st centuries. Currently he is organizing an exhibition of prints, The Urban Scene: 1920–1950, on view at the National Gallery in 2017.