Patrick Reginald Chalmers (1872–1942) was an Irish writer, who worked as a banker. His first book was Green Days and Blue Days (1912), followed by A Peck of Malt (1915).
He wrote in a number of different areas, including field sports, deerstalking and horse racing, as well biographies of Kenneth Grahame and J. M. Barrie. He was a contributor to Punch magazine and The Field, and editor of the hunting diaries of Edward VIII (as Prince of Wales). He also wrote much poetry, with topics war, dogs and cats, and Irish life, as well as hunting and fishing.
A line from his poem "Roundabouts and Swings" has passed into common parlance, though the origin is often no longer remembered.