It was discovered in 1971 during a uranium and thorium exploration by Kenny F. Larsen and was donated to the Dalhousie University in 2004. It was described but not named in 2008;[1] by then it made its way into the collection of the Royal British Columbia Museum in Victoria. It was named in 2019.[2] The holotype, RBCM P900, nicknamed Buster,[3] includes portions of the pectoral girdles, left forelimb, left hindlimb, and right pes.[2]
The name Ferrisaurus is derived from Latin ferrum (=iron) and Greek sauros (=lizard), referencing to the specimen's discovery along a railway line.[2] The epithet honours the Sustut River and Basin.[2]