Background: Patients undergoing elective procedures often utilize online educational materials to familiarize themselves with the surgical procedure and expected postoperative recovery. While the Internet is easily accessible and ubiquitous today, the ability of patients to read, understand, and act on these materials is unknown. Purpose: To evaluate online resources about anterior cruciate ligament (ACL) surgery utilizing measures of readability, understandability, and actionability. Study Design: Cross-sectional study; Level of evidence, 4. Methods: Using the term “ACL surgery,” 2 independent searches were performed utilizing a public search engine ( Google.com ). Patient education materials were identified from the top 50 results. Audiovisual materials, news articles, materials intended for advertising or medical professionals, and materials unrelated to ACL surgery were excluded. Readability was quantified using the Flesch Reading Ease, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook, Coleman-Liau Index, Automated Readability Index, and Gunning Fog Index. The Patient Education Materials Assessment Tool for Printable Materials (PEMAT-P) was utilized to assess the actionability and understandability of materials. For each online source, the relationship between its Google search rank (from first to last) and its readability, understandability, and actionability was calculated utilizing the Spearman rank correlation coefficient (ρS). Results: Overall, we identified 68 unique websites, of which 39 met inclusion criteria. The mean Flesch-Kincaid Grade Level was 10.08 ± 2.34, with no website scoring at or below the 6th-grade level. Mean understandability and actionability scores were 59.18 ± 10.86 (range, 33.64-79.17) and 34.41 ± 22.31 (range, 0.00-81.67), respectively. Only 5 (12.82%) and 1 (2.56%) resource scored above the 70% adequate PEMAT-P threshold mark for understandability and actionability, respectively. Readability (lowest P value = .103), understandability (ρS = –0.13; P = .441), and actionability (ρS = 0.28; P = .096) scores were not associated with Google rank. Conclusion: Patient education materials on ACL surgery scored poorly with respect to readability, understandability, and actionability. No online resource scored at the recommended reading level of the American Medical Association or National Institutes of Health. Only 5 resources scored above the proven threshold for understandability, and only 1 resource scored above it for actionability.