Calixarenes are supramolecular structures characterized by their “calix” shape and their easy synthetic accessibility. They are amphiphilic in nature, thus they can bear in their structure both hydrophobic and hydrophilic features as well as charged groups. They are characterized by architectural plasticity responsible for their unique fine-tuned properties that can be shaped for an array of applications. Herein, we will focus, on their diverse available applications, and give special emphasis on biocatalysis and cancer therapy as two modern directions and emerging fields of interest that have been sporadically explored in the literature and can pave the way for the discovery of novel therapeutics. This review provides the first exhaustive examination on the enhanced catalytic activity and selectivity of calixarene-based encapsulated biocatalysts towards the synthesis of bioactive molecules. The application of functionalized calixarenes in cancer therapy is also analyzed towards the spatiotemporal control they can offer in targeted drug delivery.