Here, we present a range of interactions, which we term “cryptic interactions.” These are interactions that occur throughout the marine planktonic foodweb but are currently largely overlooked by established methods, which mean large-scale data collection for these interactions is limited. Despite this, current evidence suggests some of these interactions may have perceptible impacts on foodweb dynamics and model results. Incorporation of cryptic interactions into models is especially important for those interactions involving the transport of nutrients or energy. Our aim is to highlight a range of cryptic interactions across the plankton foodweb, where they exist, and models that have taken steps to incorporate these interactions. Additionally, it is discussed where additional research and effort is required to continue advancing our understanding of these cryptic interactions. We call for more collaboration between ecologists and modelers in order to incorporate cryptic interactions into biogeochemical and foodweb models.