The company says the project now has all of the major Quebec and federal government permits required to begin construction.
The approval came just 18 months after it filed its assessment, Stornoway said.
It hopes to the open the Renard mine road, a permanent access to the project, later this year.
Stornoway also says it has named Martin Boucher to the role of vice-president of sustainable development.
The Renard Diamond Project is located about 250 kilometres north of the Cree community of Mistissini and 350 kms north of Chibougamau in the James Bay region of north-central Quebec.
It has probable mineral reserves of 17.9 million carats, with a further 17.5 million carats classified as inferred mineral resources, and 23.5 to 48.5 million carats classified as non-resource exploration upside.