The need for conventional cell culture methods with increased physiological relevancy has led to the development of spheroid formation, a method of 3D cell culture. Spheroids provide more structural, functional, and physiological relevancy which has allowed spheroids to be used extensively in cancer and stem cell research. Spheroids also have high impact potential in drug screening, but the issues with existing methods of spheroid formation are preventing their widespread use. With current methods of forming, treating, labelling, and analyzing spheroid cultures, disparate handling techniques and multiple experimental platforms are typically required. Not only are these multiple steps cumbersome, the risk of losing valuable cell material during sample manipulation is high, causing an unfavorable increase in the costs of high-value experiments such as drug discovery. This thesis demonstrates that 3D printed reverse-tapered structures can be replica molded to fabricate "one-way valve structures" into polyacrylamide hydrogel microwells that can then be used to rapidly assemble, label, and image spheroid arrays in a high-throughput format. This thesis further demonstrates the versatile use of this platform to study potential spheroid-to-spheroid invasive and migratory activity, which is not possible with existing methods of spheroid formation and culture.