British Columbia is bordered by the Pacific Ocean on its west, by the American state of Alaska on its northwest, and to the north by the Yukon and the Northwest Territories, on the east by the province of Alberta, and on the south by the U.S. states of Washington, Idaho, and Montana. The current southern border of British Columbia was established by the 1846 Oregon Treaty, although its history is tied up with lands as far south as the California border.

British Columbia's land area is 944,735 square kilometers (364,764 square miles) which is about the size of France, Germany and the Netherlands combined. It is larger than the total area of Washington, Oregon and California. British Columbia's rugged coastline stretches for more than 27,000 kilometers (16,780 miles), including deep, mountainous fjords and about 6,000 islands, most of which are uninhabited.

British Columbia's capital is Victoria, located at the southeastern tip of Vancouver Island. BC's most populous city is Vancouver, located in southwest corner of the BC mainland called the Lower Mainland. Other major cities include Surrey, Burnaby, Coquitlam, Richmond, Delta, and New Westminster in the Lower Mainland; Abbotsford and Langley in the Fraser Valley; Nanaimo on Vancouver Island; and Kelowna and Kamloops in the Interior.

Prince George is the largest city in the northern part of the province, while a town northwest of it, Vanderhoof, is at the geographic centre of the province.