The Battle of Okinawa is generally regarded as the last major battle of the Pacific War before Japan surrendered.
The battle began on April 1, 1945, when Allied forces landed on Okinawa, and major organized fighting ended on June 22. It was a lengthy campaign involving land, sea, and air forces and became the bloodiest battle of the Pacific War for many participants.
Okinawa’s capture gave the Allies airfields, anchorages, and staging areas close to Japan’s home islands. Its fierce resistance and enormous casualties shaped Allied expectations about the possible cost of an invasion of Japan.
The battle ended weeks before the atomic bombings and Japan’s surrender. Because smaller operations and isolated fighting continued elsewhere, “last major battle” does not mean the final exchange of fire anywhere in the Pacific. It refers to the scale and strategic importance of the Okinawa campaign.