Many students who experience behavioral difficulties (BD) also experience learning difficulties (LD) in school; however, little research exists on how to support the academic achievement of students with co-occurring BD/LD. Even less research exists for students who experience these co-occurring difficulties at the high school or secondary level. The goal of this synthesis was to explore the effects of academic interventions on the academic outcomes (i.e., reading, mathematics, and writing) of high school students with co-occurring BD/LD. A total of nine single-case design studies met criteria for this synthesis, including two dissertations. Four studies examined mathematics outcomes, four studies assessed reading outcomes, and two studies targeted spelling outcomes, with one study examining both mathematics and spelling. The calculated Tau-U effect sizes ranged from 0.54 to 1.0 across studies. Implications for research and practice are discussed with the goal of contributing to the small body of research on secondary-age students with co-occurring BD/LD.