Gray was born in Houston, Texas. After graduating high school, Gray attended University of St. Thomas and the University of Texas without receiving any degrees. He did receive a bachelors and masters degrees in creative intelligence, though sources vary on whether these degrees were received from Maharishi European Research University (MERU) in Switzerland or from Maharishi International University in Iowa.

Gray received his Ph.D. from the unaccredited institution, Columbia Pacific University (CPU), after completing a correspondence course. CPU was closed by California court order in 2000. The court ruled that the State of California recognizes CPU degrees earned before June 25, 1997, as "legally valid" for use in the state, but other states, such as Texas, criminalize the use of CPU degrees. This time period above included Gray's degree which he received in 1982.

Gray's seventeen books have sold over fifty million copies and have been published in forty-five languages worldwide.

Gray wrote a nationally syndicated column with thirty million readers. His column appeared in The Atlanta Journal/Constitution, New York Daily News, New York Newsday, The Denver Post, and the San Antonio Express-News. Internationally, Gray's columns appeared in publications in England, Canada, Mexico, Korea, and in Latin American and the South Pacific.

Gray is a certified family therapist and a consulting editor for Family Journal.

Gray is an international expert in the field of communication and relationships. Gray has conducted public and private seminars for over 30 years. Gray is a speaker on the national and international lecture circuit.

Gray has made guest appearances on Oprah, Good Morning America, The Today Show, The CBS Morning Show, Live with Regis, The View, Politically Incorrect, Larry King Live, The Roseanne Show and CNN. Gray has been profiled in USA Today, Newsweek, Time Magazine, TV Guide, People and Forbes.

Gray is listed as a signer of the 9/11 Truth statement.

In 2001, Gray received the Smart Marriages Impact Award.

In 2007, Gray became the Brand founder of Mars Venus Coaching Franchise.

Critics have accused him of over-simplifying human psychology into stereotypes that fail to adequately describe many people. Communication scholars have published research-based rebuttals to Gray's claims. Other scholars, such as Deborah Tannen, a professor of linguistics, have also written research-based books that challenge some of Gray's claims.

Gray was the fifth of seven children born to a Texan oilman and a stay-at-home mother.

After high school, Gray followed the Maharishi Mahesh Yogi, the founder of the Transcendental Meditation technique and for nine years he was a celibate monk, and worked as the Maharishi's assistant.

Gray divorced fellow self-help author Barbara De Angelis in 1984. Gray married his current wife, Bonnie in 1986 and they have three daughters.