Demand for online learning continues to grow at a strong pace as learners become more diverse in many ways. It is important that we use learning and design theories to shape this learning environment for success. This chapter discusses the use of multimodal design in the creation of online courses based on the science of human learning. Information processing, sensory, working, and long-term memory are discussed in terms of course design. Individual differences and similarities are explored. The question in education remains how we can match what we know about human learning to the technology modes around us to create better learner-centered environments. This chapter explores the theories applicable to multimodal eLearning and how to apply these theories in the creation of learning experiences.