Sustainability is a fast evolving movement in higher education demonstrated by a proliferation of academic programs, co-curricular initiatives, and campus projects. Sustainability is now viewed as vital to the mission of many institutions of higher education, creating a paradigm shift that librarians can help advance with their collective interdisciplinary expertise. A review of LibGuides (online resource guides) showed that academic librarians are involved with sustainability efforts on many campuses and have a role in shaping curriculum-related activities. The author administered a survey to creators of sustainability LibGuides during the spring of 2011, posting the survey on library listservs as well. Librarians returned 112 survey responses that illustrated their engagement in sustainability activities through the forging of campus partnerships with administrators, faculty, staff from the Office of Sustainability, and library colleagues. Telephone interviews conducted with 24 of the respondents showed librarians’ wide-ranging professional interest in sustainability, and their initiatives to promote its cause, including creating resources, collections, exhibits, and events; library instruction; co-teaching with faculty; serving on sustainability committees; and collaborating with sustainability faculty and staff. However, both the survey and the interviews suggest that librarians would benefit from increased collaboration and knowledge of work undertaken elsewhere. Moreover, as the needs of students and faculty studying sustainability increase, libraries need to appoint librarians with special responsibilities in this field. Included is the author’s experience as the Sustainability Studies Librarian at the University of Massachusetts Amherst and her engagement in professional development activities related to sustainability. Best practices for librarians to advance sustainability efforts are offered.