Canada is currently the largest provider of crude oil to the United States. The following data are for crude oil from pages at the following source: Energy Information Administration and http://tonto.eia.doe.gov/dnav/pet/pet_move_impcus_a2_nus_epc0_im0_mbblpd_m.htm

Update: As of Oct 2009 data: The United States produced 5,421 (39%) thousand barrels per day and imported 8,566 thousand barrels per day (61%).

The top five exporting countries to the U.S. accounted for 65 % of United States crude oil imports, while the top ten sources accounted for approximately 85 % of all U.S. crude oil imports. Middle East countries (Saudi Arabia, Iraq, Kuwait, UAE) accounted for a total of 18 % of all U.S. crude oil imports.

United States total crude oil imports Oct 2009:

December 2007: The United States produced 5,072 thousand barrels per day (34 %) and imported 9,823 thousand barrels per day (66 %) of crude oil. The U.S. currently gets a total of about 54% of its crude oil from North America (U.S., Canada and Mexico combined).

The top five exporting countries to the U.S. accounted for 73 % of United States crude oil imports, while the top ten sources accounted for approximately 88 % of all U.S. crude oil imports. Middle East countries (Saudi Arabia, Iraq, Kuwait, UAE) accounted for a total of 23 % of all U.S. crude oil imports.

United States total crude oil imports Dec 2007:

January 2007: The United States produced 5,196 thousand barrels per day (34 %) and imported 10,192 barrels per day (66 %) of crude oil. The U.S. currently gets a total of about 55% of its crude oil from North America (U.S., Canada and Mexico combined).

The top five exporting countries to the U.S. accounted for 68 % of United States crude oil imports in January while the top ten sources accounted for approximately 88 % of all U.S. crude oil imports. Middle East countries (Saudi Arabia, Iraq, Kuwait) accounted for a total of 22 % of all U.S. crude oil imports.

United States total crude oil imports Jan 2007:

Source: Energy Information Administration

The above graphic is from Senator Lugar's website: http://lugar.senate.gov/energy/graphs/oilimport.html

The following two graphs show how imports from selected countries have varied since 1960. (Source: Energy Information Administration)

The tables below list the top 15 oil exporting countries in the world [left table] and the top 15 oil producing countries in the world [right table] (Source: CIA World Fact Book).