Although cognitive load theory research has studied factors associated with motivation, these literatures have primarily been developed in isolation from each other. In this contribution, we aimed to advance both fields by examining the effects of instructional strategies on learners’ experience of cognitive load, motivation, engagement, and achievement. Students (N = 1287) in years 7–10 in four Australian high schools completed survey measures of motivation, engagement, cognitive load, and their teachers’ perceived instructional strategies and motivating style. Results suggest that teachers’ load-reducing instructional strategies were related to lower cognitive load and were positively associated with relative autonomous motivation, engagement, and achievement. Teachers’ motivating styles characterized by autonomy support and structure were also associated with reduced extraneous and intrinsic cognitive load, as well as motivation and engagement. We conclude that by using load-reducing strategies and a motivating style characterized by structure and autonomy support, teachers can reduce students’ cognitive load and improve their self-regulated motivation, engagement, and achievement. In so doing, we discuss a number of future avenues for the joint study of self-determination theory and cognitive load theory, with the aim of refining and extending both perspectives.