Abstract: Amyotrophic lateral sclerosis (ALS) is a rare neurological disorder affecting both upper and lower motor neurons. Its pathogenesis remains unclear, and there is currently no effective treatment. A growing body of research indicates that patients with ALS exhibit alterations in the expression profiles of various microRNAs (miRNAs), which are involved in multiple key pathogenic mechanisms of the disease, including misfolded protein aggregation, apoptosis, and mitochondrial dysfunction. These miRNAs also hold potential as biomarkers for the diagnosis and prognosis assessment. Furthermore, therapeutic strategies targeting miRNAs—such as the delivery of miRNAs via exosomes, artificial miRNA technology, and miRNA inhibitors—have shown promise for treatment. This article reviews the research progress on miRNAs in ALS from the perspectives of pathogenesis, biomarkers, and therapy, aiming to provide new strategies for the diagnosis and treatment of ALS.