Background: The Tegner activity scale is a patient-reported questionnaire that is frequently used to measure activity levels in patients with anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to translate, cross-culturally adapt, and validate the Tegner activity scale into Arabic. Methods: The Tegner activity scale–Arabic version (TAS-Ar) was forward and backward translated, cross-culturally adapted, and validated according to established guidelines. Seventy-five patients who underwent ACLR were instructed to complete the TAS-Ar, the International Knee Documentation Committee (IKDC) subjective knee evaluation form, and the Knee Injury and Osteoarthritis Outcome Score (KOOS) scale. The test-retest reliability of the TAS-Ar was assessed in 39 patients. Statistical tests were conducted to test the reliability and construct validity of the TAS-Ar. Results: The TAS-Ar showed excellent test-retest reliability, with intraclass correlation coefficients of 0.836 (p < 0.001). The TAS-Ar was significantly correlated with the IKDC (Spearman’s rho = 0.476, p < 0.001), all KOOS subscales (Spearman’s rho = 0.195–0.497, p < 0.05), and the KOOS total score (Spearman’s rho = 0.469, p < 0.001). Conclusions: The Arabic version of the Tegner activity scale is a reliable and valid measure that can be used to evaluate the activity level of Arabic-speaking patients following ACLR.