The flag of Montserrat has a blue field with the Union Jack in the canton and the Montserrat coat of arms on the fly side. The aspect ratio is 1:2.

Colors:

1. Blue (Pantone 280 C): #00247D
2. Red (Pantone 186 C): #C8102E
3. White: #FFFFFF
4. Green (Pantone 355 C): #009E60
5. Yellow (Pantone 116 C): #FFCD00

The Union Jack occupies the upper hoist-side quadrant, measuring 1/4 of the flag's length and 1/2 of its width. The Montserrat coat of arms is centered on the right half of the flag, with a height equal to 1/2 of the flag's width. The coat of arms features a shield with a green base and a white diagonal stripe, a woman holding a cross and a harp, and a yellow scroll with the words "AUSPICIUM MELIORIS AEVI" in black.