Kinesiophobia is a fear of physical movement and activity and is known to affect return to sports and second injury after anterior cruciate ligament reconstruction. To determine the association among landing biomechanics, knee pain, and kinesiophobia in athletes following anterior cruciate ligament reconstruction. A cross-sectional study. Clinical center of sports medicine. This study included 31 athletes who participated in sports after primary, unilateral anterior cruciate ligament reconstruction (age, median [interquartile range]: 20.0 [7.0] years; body mass index: 22.2 [2.6] kg/m2 ; time from anterior cruciate ligament reconstruction: 24.0 [23.0] months). Not applicable. Kinesiophobia was measured using the Tampa Scale for Kinesiophobia-11. Knee function included joint laxity, strength, and single-leg hop distance. Knee pain intensity during sports activities was measured using a numerical rating scale. Vertical ground reaction force was measured, and electromyography data for the vastus medialis and semitendinosus muscles during single-leg jump landing were collected. Univariate correlation analysis and multiple regression analysis were performed to identify the associations between the Tampa Scale for Kinesiophobia-11 score and outcome measures. There was no correlation between peak vertical ground reaction force and Tampa Scale for Kinesiophobia-11 score (Spearman's r= -0.17, p= .355). On multiple regression analyses, lower preparatory vastus medialis activity during landing (beta coefficient=-0.51, p< .001) and knee pain intensity (beta coefficient=0.57, p< .001) were significantly associated with greater Tampa Scale for Kinesiophobia-11 scores. In athletes who have participated in sports following anterior cruciate ligament reconstruction, lower preparatory vastus medialis activity during landing and knee pain intensity are associated with greater kinesiophobia. These findings indicate that interventions to address the landing muscle activity pattern and pain control should be performed to decrease kinesiophobia after anterior cruciate ligament reconstruction.