The 54-year-old actor applied for the licence back in February in Honolulu County on behalf of his company, Simply Organic Living, according to The Hollywood Reporter.
Harrelson was among 66 Hawaii residents who applied to open the state's first medical-marijuana dispensaries.
Applicants were required to have USD 1 million cash, plus USD 100,000 for each of their planned dispensary locations. They also must have been residents of Hawaii for more than five years.
The eight successful licensees were announced on Friday by the Hawaii Department of Health.
Six are allowed on Oahu, four on the island of Hawaii, four on Maui and two on Kauai.
Hawaii became the first US state to legalise medical marijuana 16 years ago.