OBJECTIVE: This umbrella review aimed to summarize (and update) the effectiveness of non-pharmacological and non-surgical interventions for patients with knee osteoarthritis. METHODS: The study followed the PRISMA guidelines. Manual and electronic databases were searched, to identify systematic reviews, following the P (knee osteoarthritis) I (non-pharmacological and non-surgical treatments) C (pharmacological, surgical, placebo, no intervention, or other non-pharmacological/non-surgical conservative treatments) O (pain, function, quality of life, and other knee-specific measures) model. The quality of evidence was assessed using the R-AMSTAR checklist and GRADE principles. RESULTS: The search yielded 4086 records, of which 61 met the eligibility criteria. After evaluation with R-AMSTAR, four systematic reviews were excluded, resulting in 57 included systematic reviews, with an overall score of 29.6. The systematic reviews were published between 2018 and 2022 (29.8% in 2022), conducted in 19 countries (52.6% in China), and explored 24 distinct interventions. The systematic reviews encompassed 714 trials (mean of 13 ​± ​7.7 studies per systematic review), and 59,343 participants (mean 1041 ​± ​1002 per systematic review, and 82 ​± ​59.2 per study). The majority of participants were older obese women (61.6 ​± ​4.2 years, 30.2 ​± ​3.6 ​kg/m, 70%, respectively). CONCLUSIONS: Based on the systematic reviews findings, Diet Therapy, Patient Education, and Resistance Training are strongly supported as core interventions for managing patients with knee osteoarthritis. Aquatic Therapy, Balance Training, Balneology, Dietary Supplements, Extracorporeal Shockwave Therapy, and Tai Ji show moderate support. For other interventions, the evidence quality was low, results were mixed or inconclusive, or there was not sufficient efficacy to support their use.