Nature of Operations	12 Months Ended
Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations	1.NATURE OF OPERATIONS 4Front Ventures Corp. (“4Front” or the “Company”) exists pursuant to the provisions of the British Columbia Corporations Act. On July 31, 2019, 4Front Holdings LLC (“Holdings”) completed a Reverse Takeover Transaction (“RTO”) with Cannex Capital Holdings Inc. (“Cannex”) whereby Holdings acquired Cannex and the shareholders of Holdings became the controlling shareholders of the Company (Note 11). Following the RTO, the Company’s SVS are listed on the Canadian Securities Exchange (“CSE”) under the ticker “FFNT” and are quoted on the OTC (OTCQX: FFNTF). As of December 31, 2020, the Company operates five dispensaries in Massachusetts, Illinois, and Michigan. The Company operates two production facilities in Massachusetts and one in Illinois. The Company produces the majority of products that are sold at its Massachusetts and Illinois dispensaries. The Company leases real estate and sells equipment, supplies and intellectual property to cannabis producers in the state of Washington. The Company also owns and operates Pure Ratios (which was acquired by Cannex in June 2019), a CBD-focused wellness company in California, that sells non-THC products throughout the United States. While marijuana is legal under the laws of several U.S. states (with varying restrictions), the United States Federal Controlled Substances Act classifies all “marijuana” as a Schedule I drug, whether for medical or recreational use. Under U.S. federal law, a Schedule I drug or substance has a high potential for abuse, no accepted medical use in the United States, and a lack of safety for the use of the drug under medical supervision. The head office address of the Company is 5060 North 40^th Street, Suite 120, Phoenix, Arizona, and the registered office is 550 Burrard Street, Suite 2900, Vancouver, British Columbia.

Nature of Operations

12 Months Ended

Dec. 31, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1.NATURE OF OPERATIONS

4Front Ventures Corp. (“4Front” or the “Company”) exists pursuant to the provisions of the British Columbia Corporations Act. On July 31, 2019, 4Front Holdings LLC (“Holdings”) completed a Reverse Takeover Transaction (“RTO”) with Cannex Capital Holdings Inc. (“Cannex”) whereby Holdings acquired Cannex and the shareholders of Holdings became the controlling shareholders of the Company (Note 11). Following the RTO, the Company’s SVS are listed on the Canadian Securities Exchange (“CSE”) under the ticker “FFNT” and are quoted on the OTC (OTCQX: FFNTF).

As of December 31, 2020, the Company operates five dispensaries in Massachusetts, Illinois, and Michigan. The Company operates two production facilities in Massachusetts and one in Illinois. The Company produces the majority of products that are sold at its Massachusetts and Illinois dispensaries.

The Company leases real estate and sells equipment, supplies and intellectual property to cannabis producers in the state of Washington. The Company also owns and operates Pure Ratios (which was acquired by Cannex in June 2019), a CBD-focused wellness company in California, that sells non-THC products throughout the United States.

While marijuana is legal under the laws of several U.S. states (with varying restrictions), the United States Federal Controlled Substances Act classifies all “marijuana” as a Schedule I drug, whether for medical or recreational use. Under U.S. federal law, a Schedule I drug or substance has a high potential for abuse, no accepted medical use in the United States, and a lack of safety for the use of the drug under medical supervision.

The head office address of the Company is 5060 North 40^th Street, Suite 120, Phoenix, Arizona, and the registered office is 550 Burrard Street, Suite 2900, Vancouver, British Columbia.