Online learning environments increasingly provide opportunities for interaction with and among individuals from diverse cultures. The more we acknowledge and understand the nature of diversity amongst online learners, the greater the opportunity to build effective, supportive learning environments for all. Given the almost limitless diversity between individuals an important first step is to identify dimensions that may affect the online learning experience. This paper provides a preliminary study to identify relevant diversity dimensions based on a review of the literature. It is intended to inform future research to derive principles of instructional design for creating effective online learning environments.