The 2-D semiconductors have been recognized as promising channel materials for the ultimately scaled transistor technologies beyond silicon. An essential technology enabler for 2-D semiconductor electronics is the development of dielectric materials interfaced with 2-D semiconductors. In this review article, we overview different types of dielectric materials that are suitable for different application scenarios, including high-k gate dielectrics, low- k spacers, and thermal management materials under the paradigm of 2-D semiconductor electronics. A material selection guideline for dielectric materials and the key process technology modules are discussed in detail. A special emphasis is made on how each of the dielectric technologies may enable the further scaling and practical applications of 2-D semiconductor transistors. The state-of-the-art device technologies are summarized, and the remaining challenges toward practical applications are discussed from the industrial perspective.