He was born in 1966. After graduating from Princeton University (where he edited a science fiction magazine called Infinity), Van Gelder started working as an editorial assistant at St. Martin's Press in 1988, later rising to full editor. In January 1997, he became the editor of The Magazine of Fantasy & Science Fiction upon the resignation of Kristine Kathryn Rusch. He continued working at St. Martin's until October 2000, when he bought the magazine from Edward L. Ferman to become its publisher.

During his tenure, F&SF became the second longest-running science fiction magazine, surpassing Amazing Stories in total number of issues published. It is exceeded only by Astounding/Analog. Van Gelder also began focusing on the publication of themed anthologies drawing from the magazine's back list rather than the best-of annuals published when Ferman was the magazine's publisher.

Van Gelder has made some behind-the-scenes changes to F&SF. While the Fermans published the magazine through Mercury Press, Van Gelder founded his own press, Spilogale Inc., named for a genus of spotted skunk. He has also moved the editorial offices from New York City to Jersey City, New Jersey. Van Gelder currently lives in Hoboken, New Jersey. He has been an administrator of the Philip K. Dick Award since 1995.

Richard Van Gelder, his father, was Curator of Mammalogy at the American Museum of Natural History. Lawrence Van Gelder, an uncle of Van Gelder, was a senior editor at The New York Times until his retirement in 2008.

Van Gelder is also distantly related to noted Jazz recording engineer Rudy Van Gelder. Night Shade Message Boards: June 2005: Bedfellows