With complex head and neck diseases that closely approximate crucial organs or have advanced spread and cannot be surgically resected, intensity modulated proton beam radiotherapy is favored due to its superior dose targeting through magnetic manipulation of the proton energy. A radiation mask and an oral positioning device immobilize craniofacial, cervical, and oral structures for accurate and reliable radiation delivery. Widely available prefabricated thermoplastic oral positioning devices are manufactured in standardized forms and materials that unpredictably affect the proton beams’ pathways and range. This technique article showcases a workflow that combines analog and digital dental techniques to produce a customized 3D‐printed oral positioning device within 2 appointments.