Oprah Winfrey, who is part of the cast of The Butler with Rickman, posted a picture on her Twitter feed which shows the Harry Potter actor in black tie dressed as Reagan.
Jane Fonda also features in the photograph as Reagan's wife Nancy, alongside Winfrey and The Butler director Lee Daniels.
The Butler tells the story of Cecil Gaines (Forest Whitaker), a character based on real-life figure Eugene Allen, who served eight different American presidents during his time at the White House.
Winfrey plays Gaines's wife in the movie.
The film's ensemble cast also features John Cusack, David Oyelowo, Liam Neeson, Liev Schreiber and Robin Williams, with James Marsden and Minka Kelly playing John F Kennedy and Jackie Kennedy.
The Butler is due to be released in 2013.