What do the letters “V-J” mean in the name V-J Day?

The letters V-J mean Victory over Japan.

V-J Day is short for Victory over Japan Day, the name used for the Allied celebration of Japan's surrender in World War II. In the United States, the term most often refers to August 14 or 15, 1945, when news of Japan's acceptance of the Allied surrender terms became public. Japan's formal surrender ceremony followed on September 2.

The wording parallels V-E Day, or Victory in Europe Day, which marked Germany's surrender in May 1945. V-J therefore identifies the defeated country rather than a location, military operation, or political agreement. The phrase “Victory in Japan” is a common but inaccurate expansion of the initials.

Different countries and time zones used different dates for public celebrations. In Japan, August 15 is associated with the emperor's surrender broadcast. Many historians use September 2 for the legal end of the war because that was when the Instrument of Surrender was signed aboard USS Missouri.

The term remains common in historical writing, museums, and commemorations of the Pacific War.