There is a growing interest in cross-domain interactions in developmental research. Changes in one domain can have seemingly unexpected effects on another domain—a theoretical concept known as developmental cascades. An area of burgeoning research in child studies is motor-language cascades, whereby a gain in motor skill has downstream effects on language development by changing the way the child interacts with objects and people in their environment. Down syndrome (DS) is associated with syndrome-specific features and within-syndrome variability in motor skills and language. To map potential evidence for motor-language cascades in this neurodevelopmental disorder, this scoping review identified papers that reported motor and language data in children with DS. Results found that motor functioning and language functioning have often been reported together, but not analyzed together, in studies of children with DS. In the few studies that analyzed motor-language links, a positive relation was found. Analyzing links between motor and language, as well as other cognitive functions, when such data is available is needed to fully characterize developmental cascades in DS. Further, designing prospective longitudinal studies to examine motor and language functioning via a developmental cascades lens may have broad clinical applications for children with DS.