There is an urgent need to develop new anti-inflammatory compounds due to the versatility of their applications and the side effects associated with currently used nonsteroidal anti-inflammatory drugs (NSAIDs). Compounds containing the 1,2-benzothiazine 1,1-dioxide moiety in their structure have demonstrated a broad range of pharmacological activities, among which the anti-inflammatory effect is the most well-documented. Numerous in vivo studies have confirmed the effectiveness of these compounds in alleviating pain and inflammation. In turn, in vitro studies have shown that 1,2-benzothiazine derivatives exhibit anti-inflammatory activity not only through the classical mechanism involving the inhibition of cyclooxygenase (COX) but also through modern, more complex mechanisms. These innovative mechanisms include inhibition of microsomal prostaglandin E2 synthase-1 (mPGES-1) or 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), suppression of pro-inflammatory cytokines, and modulation of kinase activity involved in inflammatory processes. Importantly, many studies have shown that some new 1,2-benzothiazine 1,1-dioxide derivatives exhibit even stronger anti-inflammatory activity than traditional NSAIDs, making them promising candidates for new drugs targeting inflammation-related diseases. This paper presents a review of 1,2-benzothiazine 1,1-dioxide derivatives investigated for their anti-inflammatory activity in both in vivo and in vitro models, taking into account their various mechanisms of action and potential directions for further research.