Merrill's Marauders (named after Frank Merrill) or Unit Galahad, officially named the 5307th Composite Unit (Provisional), was a United States Army long range penetration special operations jungle warfare unit, which fought in the South-East Asian theatre of World War II, or China-Burma-India Theater (CBI). The unit became famous for its deep-penetration missions behind Japanese lines, often engaging Japanese forces superior in number.

In slightly more than five months of combat, the Marauders had advanced 750 miles (1,210 km) through some of the harshest jungle terrain in the world, fought in five major engagements (Walawbum, Shaduzup, Inkangahtawng, Nhpum Ga, and Myitkyina) and engaged in combat with the Japanese Army on thirty-two separate occasions, including two conventional defensive battles with enemy forces for which the force had not been intended or equipped. Battling Japanese soldiers, hunger, fevers, and disease, they had traversed more jungle terrain on their long-range missions than any other U.S. Army formation during World War II.

The men of the Merrill's Marauders enjoyed the rare distinction of having each soldier awarded the Bronze Star. In June 1944, the 5307th Composite Unit (provisional) was awarded the Distinguished Unit Citation:

The unit must display such gallantry, determination, and esprit de corps in accomplishing its mission under extremely difficult and hazardous conditions as to set it apart and above other units participating in the same campaign.