The Western International League was a mid- to higher-level minor league baseball circuit in the Pacific Northwest United States and western Canada that operated in 1922, 1937 to 1942, and 1946 to 1954. In 1955, the Western International League evolved to become the Northwest League, which is still playing today.

Informally known as the "Willy" loop, The Western International League operated in 1922, 1937 to 1942, and 1946 to 1954. In 1955, the league changed its name to become the Northwest League, and operated through 2019 as a Class A-Short Season loop under that name. In the minor league reorganization of 2021, most Northwest League teams became members of the High-A West circuit, before resuming the former name in 2022

The WIL consisted of teams in the U.S. states of Oregon, Washington, and Idaho, and the Canadian provinces of British Columbia and Alberta. It was a Class B league through 1951 and was upgraded to Class A in 1952. In its final season in 1954, it started with ten teams in Calgary, Edmonton, Lewiston, Salem, Spokane, Kennewick–Richland–Pasco (playing as "Tri-City"), Vancouver, Victoria, Wenatchee, and Yakima. Three teams did not finish the season (Spokane, Victoria, Calgary). The final champion was the Vancouver Capilanos, who swept the Lewiston Broncs in four games. Vancouver was the first half champion while third-year Lewiston won the second half.

Throughout much of the 1930s and 1940s, its teams were largely unaffiliated with major league farm systems and provided talent to the strong Pacific Coast League of the era.