During the 21st century, library and information scholars have set out to theorize the role of public libraries as public spheres. Most of this research is engaging with Habermas’ early work on the structural transformation of the public sphere. Even though Habermas has continued to develop his theories on the public sphere and deliberative democracy throughout his carrier, library and information scholars have to a limited degree engaged with his more recent work. Simply relying on Habermas’s early work when theorizing public libraries as public spheres is limiting, but in addition to getting up to speed on Habermas’ theoretical development, library and information scholars should also familiarize themselves with a broader set of public sphere theories. In this paper, I will give a short presentation of Habermas’ work of relevance for public libraries, I will give a short presentation of some additional theories of public spheres, and I will present key concepts in studies of public libraries as public spheres within library and information science. I will conclude with some thought on how to move forward when theorizing public libraries as public spheres within library and information science.