Rob was born to Margaret and Cedric Johnson on March 7, 1955, in Memphis, Tennessee. He was the oldest son of three children. His older sister is Kitty and his younger brother is Bert. He was previously married to Mia Vahlberg and they had three daughters: Darcy, Elaine and Perry. Rob was a 1973 graduate of Tulsa Memorial High School, a 1979 graduate of OSU. He gradu- ated with a B.S. in Business.

Rob started his professional career in the oil business and was elected to the Oklahoma State House of Representatives in 1988, where he served for three terms. He was appointed to run the school land office by Governor Keating. He had his own government affairs business. Rob was a member of Asbury United Methodist Church where his memorial service was held on Sunday April 10, 2011.