3D printing technology has an enormous potential to apply to chemical engineering education. In this paper, we describe several designs of 3D printed mesoreactors (Y-shape, T-shape, and Long channel shape) using the following steps: reactor sketching, CAD modeling, and reactor printing. With a focus on continuous plug flow mesoreactors (PFRs, i.d. = 2 mm), fluid mixing phenomena were explored by using a passive mixing method. The small channel of mesoreactors facilitates the stability of a laminar flow in the system at low Reynolds number. With changes in flow rates (0.2 and 4.0 mL/min) and channel geometry (0° and 90° outlet angle), fluid mixing was controlled. Our results provided that 3D printed mesoreactors can be possibly used in teaching fluid dynamics, chemical kinetics, and reaction engineering, which are main courses of the chemical engineering undergraduate program. Furthermore, the cost of mesoreactor printing was suitable (<$1.00/microreactor) for education.