<p>Coastal dunes are among the most imperiled ecosystems and are prime examples of ‘bio-geomorphologic’ systems wherein geomorphology impacts the vegetation and vegetation impacts geomorphology. This leads to distinct plant communities that trap sand differently which branches into different outcomes in dune shape, size, services, and biodiversity. Understanding how these plant communities form is crucial to protecting and restoring these vital ecosystems. In this review, we examine the history of coastal dune plant community assembly theory from Cowles’ early concepts of succession to modern theories. We found that coastal dunes have had a critical impact on assembly theory history by building on both successional and niche theories throughout the 1900s, but less so in recent years. To quantify and confirm these impressions, we performed a systematic review using the search term “Coastal Dune Community Assembly”, which yielded 37 papers. The ‘Environmental Filtering Metaphor’ was the most common assembly theory discussed (38%) followed by niche theory (19%) and the Stress-Gradient Hypothesis (16%). Notably, only 49% of the papers statistically tested these theories. Despite the overall lack of literature addressing dune plant community assembly, our synthesis suggests possible avenues of future study. There appears to be mixed and contradictory support for the Stress-Gradient Hypothesis, which future efforts should seek to disentangle. Additionally, the potential for the integration of functional traits is often noted as a promising direction (38%). More studies directly testing assembly theories and syntheses seem to be a promising direction in the protection and restoration of coastal dunes across the globe.</p>