The purpose of this study was to investigate the current status of sustainability education in Massive Open Online Courses (MOOCs). Sample MOOCs were searched for from seven popular platforms and three search engines. After screening, 51 courses were identified as the final sample. Course description, content outlines, reading materials, recommended textbooks and discussion threads were coded to obtain insights into sustainability education learning contents, pedagogical methods, and interaction situations. Results indicated that: (1) Edx and Coursera are platforms that incorporated the most sustainability-related courses, and most instructors were senior academics with the title of professor. American and European countries outperformed other English speaking countries as early birds in sustainability education using MOOCs. The average course length of our MOOC samples is 7.6 weeks, which is much shorter than a typical face-to-face college course; (2) Current MOOCs provided mainly introductory-level courses without prerequisites. Fourteen sustainability-related hot topics and five most popular textbooks were identified; (3) The pedagogical means used most frequently were discussion forums and lecture videos, while pedagogies such as team-based learning were not used to a large extent; (4) Learner interaction flourished in MOOCs, and sub-forums regarding Lecture Reflection, Welcome and Introduction were posted with most threads, replies, and votes. Our findings suggest that the MOOC is an innovative method in sustainability education and research. A variety of information and strategies could be used when preparing sustainability-related MOOCs
