Mike Thelwall, University of Wolverhampton, UKPurpose: This article investigates if and why audience gender ratios vary between museum YouTube channels, including for museums of the same type. Design/methodology/approach: Gender ratios were examined for public comments on YouTube videos from 50 popular museums in English-speaking nations. Terms that were more frequently used by males or females in comments were also examined for gender differences. Findings: The ratio of female to male YouTube commenters varies almost a hundredfold between museums. Some of the difference could be explained by gendered interests in museum themes (e.g., military, art) but others were due to the topics chosen for online content and could address a gender minority audience. Practical implications: Museums can attract new audiences online with YouTube videos that target outside their expected demographics. Originality/value: This is the first analysis of YouTube audience gender for museums.