Data visualizations are increasingly used to communicate essential insights. However, these visualizations are inaccessible to screen-reader users, further exacerbating the digital divide. Evidence shows that creators have minimal knowledge about accessibility. To address these concerns, this book provides foundational and cutting-edge knowledge about visualization accessibility. Starting with a brief history of data visualizations and shedding light on the disenfranchisement caused by their inaccessibility, the author presents a detailed overview of the modalities used for visualization accessibility, highlighting their advantages and shortcomings. In addition, the book delves into various interaction mechanisms, exploring user agency and closing with future avenues to make visualizations equitably accessible. Overall, Exploring Data Visualization Accessibility enables students, researchers, and practitioners to learn more about this topic and employ best practices in creating visualizations that can benefit all.