An actifan, fanzine editor and filksinger, Juanita Coulson has been widely known in filk music circles since the 1950s for her singing and songwriting. At NorthAmeriCon she managed to out-sing a riverboat whistle.
For thirty-three years, she co-edited the mimeographed science fiction fanzine Yandro with her husband Buck. Yandro was nominated for a Hugo Award every year from 1958–1967; it won the award in 1965, thus making Coulson one of the very first women editors to be so honored.
She co-edited Vandy with Buck Coulson and also published the early Star Trek fanzine, ST-Phile. She was extremely skilled at handstencilling fanartists' illos.
She is also a science-fiction and fantasy pro. Her first novel, Crisis on Cheiron, came out in 1967. During her writing career, she has collaborated with other authors such as Marion Zimmer Bradley. One of her better-known novel series is the Children of the Stars books. Several of her novels concern the exploitation of "primitive" intelligent species or first contact.
She was nominated for DUFF in 1972 and 2012, losing both times, before being nominated again and winning in 2014.
She is the mother of Bruce Coulson.