We tested host plant suitability of 10 taxa in the Rhamnaceae for successful preoverwintering development of soybean aphid, Aphis glycines Matsumura (Homoptera: Aphididae). In the laboratory, we offered each gynopara and ovipara a single member of each putative host plant and measured survivorship and fecundity. Rhamnus cathartica L. and Rhamnus alnifolia L’Héritier were confirmed as suitable host plants, and eight other taxa were confirmed as unsuitable. This study supports results from a companion study in which soybean aphids were offered multiple members of the Rhamnaceae in field cages. Of the two suitable host plants, R. cathartica supported greater longevity and oviposition rates in oviparae. The importance of R. cathartica as an overwintering host to soybean aphid ecology and management is discussed.