Herridge, R, Turner, A, and Bishop, C. Monitoring changes in power, speed, agility, and endurance in elite cricketers during the off-season period. J Strength Cond Res 34(8): 2285-2293, 2020-The purpose of this study was to monitor changes in power, speed, agility, and endurance in elite cricketers during the 20-week off-season period. Fourteen elite male cricketers (age 26.2 ± 5.3 years; height 180.8 ± 8.5 cm; mass 83.5 ± 6.7 kg) conducted a physical testing battery in week 1 and week 18 of the off-season period. The testing included a yoyo intermittent recovery test, bilateral and unilateral countermovement jumps, squat jump, broad jump, drop jump (to calculate reactive strength index), proagility, and 5-, 10-, 20-m sprint tests. Results showed significant improvements (p ≤ 0.05) in all fitness tests except for the pro-agility test (p = 0.076), with effect sizes ranging from 0.26 to 2.8 across the test battery. The results of this study show that the off-season period in cricket allows adequate time for significant improvements of physical qualities needed for the demanding in-season schedule of the sport and provides normative values for an elite cricket population.