She was born in Berkeley, California. She attended Berkeley schools through high school followed by three years at San Francisco State College (now University).In November 1969 she married Donald Simpson and divorced in February 1982. She has no children.

Writing for over 35 years, Yarbro has worked in a wide variety of genres, from science fiction to westerns, from young adult adventure to historical horror. She is the author of over 70 novels and numerous short stories. She is probably best known for her series of historical horror novels about the vampire Count Saint-Germain. She also has published numerous volumes in a popular series of channeled wisdom from the entity Michael in the Messages from Michael series.

Yarbro's contribution to the horror genre has been recognised in a variety of ways: she was named a Grand Master at the World Horror Convention in 2003, and in 2005 the International Horror Guild named her a "Living Legend". She has also received the Knightly Order of the Brasov Citadel from the Transylvanian Society of Dracula. In 2009 the Horror Writers' Association presented Yarbro with the Bram Stoker Lifetime Achievement Award. Additionally, two of her novels, The Palace (1979) and Ariosto (1980) were nominated for the World Fantasy Award, neither winning.

On average, Yarbro writes three to four books a year, and one or two short stories and/or essays. She writes six hours per day, six days per week except when traveling. Five days a week she spends three to four hours doing research.

Aside from writing, she has worked as a cartographer, has read tarot cards and palms, and has composed music, all of which she continues to do. Over the years she has studied seven different instruments, voice, and musical theory: composition, voice, and piano have continued to be active interests for her. The newsletter, Yclept Yarbro, about her and her writings has been published since 1995 by Lindig Hall Harris More about Chelsea Quinn Yarbro.

Pseudonyms:

• Quinn Fawcett with her writing projects with Bill Fawcett
• Trystam Kith [2-volume nasty vampires]
• Terry Nelson Bonner [vol. 5 in The Making of Australia series]
• T. C. F. Hopkins [non-fiction history]
• Vanessa Pryor [romance; 1 title "Taste of Wine"]

Messages from Michael is the first in a series of four books that chronicles a three-decade-long "conversation" between a group of friends surrounding Sarah Chambers (d. 1998) and a channelled, spiritual teaching entity that has come to be known as Michael. As of November 2007 this conversation continues, as the Michael group continues to conduct closed sessions in the San Francisco Bay Area. A core concept of the teachings is: "all choices made are equally valid."

Chelsea Quinn Yarbro's book presented a heavily fictionalized version of Sarah Chambers' group, identifying her under the pseudonym of Jessica Lansing. Ms. Yarbro owns the copyright to the group's work and published three more books on the subject, containing edited channeling transcripts as well as additional background material.

The Michael books

• Messages from Michael on the nature of the evolution of the human soul (1979), ISBN 0-872235-26-2
• Messages from Michael; 25th Anniversary Edition (2005) ISBN 978-0974290744
• More Messages from Michael (March 1986), ISBN 0-425-08662-3
• Michael's People (July 1988), ISBN 0-425-10932-1
• Michael for the Millennium (1995), ISBN 0-425-15074-7

The Saint-Germain Cycle

• Hôtel Transylvania (1978) is coincident with the historical Count Saint-Germain, set in the France of Louis XV, and involves his interaction with a cult of Satan-worshippers who threaten various men and women of his acquaintance. His principal romantic interest is a young lady, Madeline de Montalia, whom he changes at the end of the novel and who is a frequent companion in books with later settings.
• The Palace (1978) is set in Florence in the time of Lorenzo de Medici and Botticelli, who appear as characters.
• Blood Games (1980) is set in Nero's Rome. His romantic interest in Olivia Clemens, a battered wife whom he changes and who survives (and is featured in her own series of novels) until a fire in the 16th Century.
• Path of the Eclipse (1981) involves St. Germain's escape from Genghis Khan through Tibet and India.
• Tempting Fate (1982) is set in Europe after World War I and chronicles the rise of the Nazi party in Germany.
• The Saint-Germain Chronicles (a short story collection) (1983) In five stories set in the 19th and 20th century, St. Germain explores various parts of his life. The final story, "Cabin 33", is the latest story in the canon, set at a dude ranch in the American West owned by St. Germain and Roger, and concludes with St. Germain and de Montalia deciding to see if they can break with vampire tradition and live together as husband and wife.
• Out of the House of Life (1990) principally concerns the adventures of de Montalia on an 1810 archaeological expedition to Egypt, punctuated with long letters from St. Germain which contain information she uses to find artifacts left behind from his "life" there. However, St. Germain only appears as a character directly for a short period at the end of the novel.
• Darker Jewels (1993) is set in the Russia of Ivan the Terrible.
• Better In The Dark (1993) is set in Germany in the 10th century.
• Mansions of Darkness (1996) features St. Germain in Spanish America in the 17th century.
• Writ in Blood (1997) features St. Germain as a secret agent of Russian Tsar Nicholas II, attempting to patch the ties of blood between the European royal families and prevent the outbreak of World War I.
• Blood Roses (1998) is set at various locations in France during the Plague years.
• Communion Blood (1999) is set in Rome in the late 17th century.
• Come Twilight (2000) is set in Moorish Spain.
• A Feast in Exile (2001) is set in India at the time of Tamurlane's invasion.
• Night Blooming (2002) is set in the Frankish kingdom of Charlemagne.
• Midnight Harvest (2003) features St. Germain's visit to the United States following the events of Tempting Fate.
• Dark of the Sun (2004) is set in China in the 6th century.
• States of Grace (2005) is set in Western Europe in the 1530s.
• Roman Dusk (2006) is set during second century BCE Rome of Heliogabalus
• Borne in Blood (2007) is set in Switzerland in the 1810s
• Saint-Germain: Memoirs (2007, short story collection) features St. Germain in various time periods
• A Dangerous Climate (2008) is set in 18th century St Petersburg, Russia
• Burning Shadows (2009) is set in 5th century Hungary and Romania

The Atta Olivia Clemens novels

• A Flame in Byzantium (1987) is set in 6th century Constantinople during the reign of Justinian I
• Crusader's Torch (1988) is set in 1189 AD during the Christian Crusades in the Middle East
• A Candle for D'Artagnan (1989) is set in France during the 17th century reigns of Louis XIII and Louis XIV

The Madelaine de Montalia novels

• Out of the House of Life (1990) is set in an archeological expedition to Egypt during the 1820s.
• In the Face of Death (2004) is set in the United States just before and during the Civil War.

Other novels

• Ariosto (1980)