Riverside Quarterly was a science fiction fanzine edited by Leland Sapiro.
The genesis of Riverside Quarterly began in 1953 with Inside, started by Ron Smith which was merged in 1954 with Science Fiction Advertiser (1952-1953, which had begun as Fantasy Advertiser published from April 1946 to November 1951), and was renamed Inside and Science Fiction Advertiser. It was published under this title for 3 years, during which it won the Hugo Award for Best Fanzine. It then ran a further year as Inside Science Fiction. It ceased publication for 4 years and was then revived for 3 issues as Inside with editor Jon White and Ron Smith as Assistant Editor. The last issue appeared as Inside-Riverside Quarterly,the transition between Inside with White as editor and new editor Leland Sapiro, who would rename the zine Riverside Quarterly. The first issue appeared in 1964.
To further complicate matters, Sapiro moved to Saskatoon, Saskatchewan in Canada and then Regina, Alberta, Canada in the 1970s, then Florida, U.S.A. in 1875, Texas, in the 1980s, and Louisiana, in the 1990s.
Riverside Quarterly featured articles, essays, criticism, fiction, poetry, art work and reviews.
Contributors included Sid Birchby, Algis Budrys, James Castle, Arthur Jean Cox, Samuel Delany, Philip Jose Farmer, Thomas Disch, William Fagan, Barbara Floyd, Janet Fox (Scavenger's Newsletter), Jim Harmon, Gordon James, Robert W. Lowdnes, Sandra Miesel, Richard D. Mullen, Kris Neville, Robert Plank Offutt, Edith Ogutsch, , Alexei Panshin, Nick Perry, Joyce Pollard, Lance Robinson, Andy Ross, Pamela Sargent, Darrell Schweitzer, John Sladek, Tom Slate, Harry Warner, Jr., Peter Warren, Roy Wilkie, Jack Williamson, Roger Zelazny, and George Zebrowski.
Art work was by Charles Schneeman, among others.