Susan Sackett was born in New York City on December 18, 1943, raised in Connecticut and moved to Florida after graduating from Hillhouse High School in New Haven. She received her Bachelor of Arts (1964) and Master of Education (1965) degrees from the University of Florida at Gainesville. After teaching elementary school in Miami for two years, she moved to Los Angeles, where she taught for a short time. She quit her teaching job to work in the entertainment industry, spending four years with the National Broadcasting Company (NBC) as a Publicity Assistant and Commercial Coordinator.

In 1974, she began an association with Gene Roddenberry, creator of the television legend Star Trek, serving as his personal executive assistant for over 17 years until his death in October 1991. She also served as his production assistant on The Motion Picture and worked closely with him on the next five Star Trek films. In addition, she served as Production Associate during the first five seasons of the television series The Next Generation.

Sackett and her writing partner, Fred Bronson wrote the TNG episodes "Menage a Troi" (teleplay) and "The Game" (story credit only). Additionally, while working full time as Roddenberry's assistant, Sackett wrote three books about Star Trek: Letters to Star Trek, Star Trek Speaks!, and The Making of Star Trek: The Motion Picture (with Gene Roddenberry).

Another book, Star Trek: The First 25 Years, co-authored with Gene Roddenberry, was purchased by Pocket Books, although not published due to the publisher's legal entanglements. Instead, it became the basis of the 1994 book, Star Trek: 'Where No One Has Gone Before': A History in Pictures, by J. M. Dillard. In the Fall of 1993, Billboard Books published Prime-Time Hits, her third Billboard book, and Sackett's book Hollywood Sings! was released in 1995.

In 2002, her controversial book Inside Trek: My Secret Life with Star Trek Creator Gene Roddenberry (Hawk Publishing Group) was released, detailing her decade and a half-long romantic and intimate involvement with her employer and mentor.

She is author of other books also related to the film and television industry, including You Can Be a Game Show Contestant and Win! (Dell Books, 1982), co-written with Cheryl Blythe. Following her own advice as outlined in the book, in 1985 Susan went on Jeopardy! and won $10,000 in cash and prizes.

Sackett and Blythe also co-authored Say Goodnight, Gracie! - The Story of Burns and Allen (E. P. Dutton, 1986; paperback edition, Prima Publishing, 1989). In 1990, The Hollywood Reporter Book of Box Office Hits was published by Billboard Publications, with an updated and revised version released in 1995.

Susan Sackett is a secular humanist and has been active in Humanism since 1989. Since 2000, she has been president of Humanist Society of Greater Phoenix. She is on the Board of Directors of the American Humanist Association, a member of MENSA, the Academy of Television Arts & Sciences (ATAS), and Writers Guild of America (WGA). She currently resides in Arizona.