Knowledge gaps exist on association between law enforcement officer (LEO) anthropometric characteristics and perceived body armour fit, armour discomfort, and armour-caused pain. This study assessed the correlation and identified influential torso dimensions for armour sizing and design applications. Nine-hundreds and seventy-four LEOs across the U.S. participated in a national study on LEO armour use and body dimensions. Perceived ratings of armour fit, armour discomfort, and body pain were found moderately correlated with each other. In addition, armour fit ratings were associated with certain torso anthropometric characteristics, such as chest circumference, chest breadth, chest depth, waist circumference, waist breadth (sitting), waist front length (sitting), body weight, and body mass index. LEOs who reported armour poor fit, armour discomfort, and armour-caused pain had a larger mean of body dimensions than the “armor good fit” group. More women than men had poor fit, discomfort, and body pain in the use of body armour. Practitioner summary: The identified influential body measurements can be used as the “drivers” for multivariate analyses to develop an improved armour sizing system to further LEO protection. The study also suggests consideration of gender specific armour sizing systems to accommodate differences in torso configurations between male and female officers and to resolve the concern that more female officers had poor armour fit than male officers.