Digital ethnography can be used to study online audiences and virtual communities built around museum content. Virtual museum visitors can participate in online museum spaces, including interactive online galleries, virtual three-dimensional museum simulators, or museum profiles on social network sites or blogs. These online environments can include recording tools, to trace all of the activities of the users and to display all of the visible records. This chapter discusses challenges, ethical implications, and online research opportunities of the digital ethnographic methodology employed to study online museum audiences. It illustrates the method through empirical studies of online communities at internationally recognized museums. Digital ethnographic research conducted in online museum communities can inform Digital Humanities and incorporate perspectives from visitor studies.