est Fraser was founded in 1955 when three brothers, Henry H. Ketcham Jr., William P. Ketcham, and Samuel K. Ketcham, acquired a small lumber planing mill at Quesnel, B.C. From 1955 to 1979 the business expanded through the acquisition of a number of sawmills and related timber rights in the interior of British Columbia. The company took on its present form in 1966 with the amalgamation of a group of companies under the Company Act (British Columbia).

In 1979 West Fraser formed the Quesnel River Pulp joint venture to construct and operate a pulp mill at Quesnel.

In 1981, West Fraser expanded into the kraft paper and containerboard industry by acquiring a 40% interest in Eurocan Pulp & Paper. Eurocan owned a linerboard and kraft paper mill, two sawmills, and partial interests in two joint venture sawmills. West Fraser increased its ownership in Eurocan to 50% in 1984 and in 1993 acquired the remaining 50%.

Alberta Newsprint Company was formed in 1989 when West Fraser entered into a joint venture to construct and operate a newsprint mill at Whitecourt, Alberta.

In 1995 West Fraser acquired the Blue Ridge sawmill and the Ranger Board MDF plant, both at Blue Ridge, Alberta. This same year saw the acquisition of Slave Lake Pulp mill at Slave Lake, Alberta.

The WestPine MDF plant at Quesnel began operations in 1996.

In 1999 West Fraser acquired a plywood plant in Edmonton and a stud mill and veneer plant at Slave Lake.

In 2000 West Fraser acquired two sawmills located in the southern United States as well as a 50% interest in a sawmill at Red Earth, Alberta.

In May 2001, West Fraser sold the Revy operations to Rona Inc. This same year, West Fraser acquires Ainsworth Lumber Co. Ltd.'s sawmill located at Chasm, BC.

On November 1, 2002, West Fraser increased in its ownership in Quesnel River Pulp to 100%.

On December 31, 2004 West Fraser completed its acquisition to purchase Weldwood of Canada Limited from International Paper Company. This transaction made West Fraser the 3rd largest lumber producer in North America and is expected to enhance its position as a performance leader among integrated forest products companies.

With this purchase West Fraser acquired 7 sawmills, 2 plywood plants, 1 laminated veneer lumber plant and 2 pulp mills, along with approximately 3,000 employees, located throughout the interior of BC and Alberta.

West Fraser currently holds timber-cutting rights in British Columbia and Alberta representing 6.8 M³ of AAC from which harvesting operations provide raw materials for its manufacturing operations. It has also entered into a long-term agreement for the supply of the majority of fibre required by its sawmills in the southern United States. All of the fibre requirements of West Fraser's pulp and paper mills and panel plants can be satisfied, directly or indirectly, from its own operations.

On October 31, 2006 West Fraser sold its interest in the Burns Lake and Decker Lake sawmills.

On March 31, 2007 West Fraser acquired 13 new sawmill in the southern U.S. from International Paper. The new mills have a combined annual production capacity of approximately 1.8 billion board feet of southern yellow pine lumber. With this acquisition, West Fraser became the second largest lumber producer in North America.