Sidewalk Sam is the pseudonym of Robert Charles Guillemin (born 4 May 1939), a Boston-based artist who resides in Newton, Massachusetts. He is best recognized for his reproductions of European masterpieces, chalked or painted on the sidewalk. Following an accident in 1994 that left him paralyzed, Guillemin increased his focus on large participatory art projects for communities and businesses. His motto, on a stickie at the top of his computer, reads "Entertain, Inspire, Empower and Unite".
In the summer of 1973, Guillemin first took to the streets of Boston and Cambridge, Massachusetts to draw famous artworks on crowded street corners where passersby filled a bucket with change. By the early 1980s, Guillemin found business sponsors for his street artworks and shifted to longer-lasting acrylic paints. Throughout the 1980s and 1990s, Guillemin also organized chalk-drawing festivals, open-air art exhibits, and public art events that engaged participants in the creation of large mosaics, murals, and banners. In 1990 and 1991, Guillemin organized the Boston Artists’ Summer Festival.
In 1994, Guillemin fell 30 feet from the roof of his home  which paralyzed him from the chest down and made him into a wheelchair user. After his accident, Guillemin returned to street painting and continues to organize participatory art events in Boston and internationally.
As an undergraduate, Guillemin attended Boston College, the University of Illinois, and, finally, Boston University, where he received a Bachelor of Fine Arts (BFA) in 1962. While at Boston College, he also attended courses at the School of the Museum of Fine Arts (a.k.a., Boston Museum School).
After graduation from Boston University, Guillemin traveled to Paris and attended courses at the École des Beaux-Arts and the Académie de Grande Chaumière. Starting in 1965, Guillemin studied for his master’s degree in painting at Boston University, where Walter Tandy Murch (1907–1967) was the chief graduate painting faculty. Guillemin received his MFA in 1967.
- Structural Surfaces: April, 1971, the Rose Art Museum at Brandeis University.
- Quick Sketches: December, 1971, the Institute of Contemporary Art on Beacon Street in Boston.
- Flush with the Walls: June 15, 1971, Boston Museum of Fine Arts. Guillemin worked with a group of five artists (Kristin Johnson, Todd McKie, Martin Mull, David Raymond and Jo-Sandman) to stage a protest event/exhibition in a men's restroom located in the museum's lower level.
Awards and recognitions
- Official Screever of the Commonwealth of Massachusetts, 1984.
Ernst Guillemin was his uncle, and he is the younger brother of M.I.T. mathematician Victor W. Guillemin, recipient in 2003 of the American Mathematical Society's Leroy P. Steele Prize for Lifetime Achievement. His brother-in-law is revolutionary historian Ray Raphael.
- "In Boston, There Is A Danger of Stepping On, Say A Rembrandt," by Laird Hart, The Wall Street Journal, July 17, 1974, page 1.
- "Artist's Work Moves out onto the Streets in Summer Festival," by Christine Temin, The Boston Globe, August 2, 1991 (Arts Section)
- Nicas, Jack, Sidewalk Sam paints verses on Longfellow July 2010, The Boston Globe
- "Welcome back, Sidewalk Sam," The Boston Globe, 27 October 1995, page: 41.
- "Art Bog: Squeeze at Brandeis Hits Rose Museum Exhibit," By Charles Giuliano, Boston Herald Traveler, April 10, 1971.
- Painting in Boston: 1950-2000 (exhibition catalogue), eds. Rachel Rosenfield Lafo, Nicholas Capasso, and Jennifer Uhrhane (Lincoln, Mass: DeCordova Museum and Sculpture Park; Amherst, Mass.: distributed by University of Massachusetts Press, 2002), page: 34-36.
- "News, Events and Announcements". ams.org. Retrieved December 21, 2010.