Sulfur-containing compounds are ubiquitous in chemistry, pharmacy, and materials sciences. As sulfur-containing compounds, thiopyranones and thiopyranthiones, or more specifically, 2H-thiopyran-2-ones, 2H-thiopyran-2-thiones, 4H-thiopyran-4-ones, and 4H-thiopyran-4-thiones, have been widely studied and new synthetic methods have emerged as a consequence of their important biological activities and unique reactivities. This chapter is an update to the earlier Science of Synthesis review of these compounds (Section 14.8), and covers literature published up until 2019.