This book constitutes the thoroughly refereed workshop proceedings of the 8th International Workshop on Structured Object-Oriented Formal Language and Method, SOFL+MSVL 2018, held in Gold Coast, QLD, Australia, in November 2018. The 11 revised full papers included in the volume were carefully reviewed and selected from 21 submissions. They are organized in the following topical sections: programming and testing; verification and validation; semantics; and blockchain.