Background: Postbiotics are bioactive compounds derived from inactivated probiotic microorganisms that show potential for preventing and treating inflammatory diseases. This review aimed to evaluate the evidence on their therapeutic effects in inflammatory conditions. Methods: A search of PubMed, Scopus, and Web of Science databases from 2014 to 2024 identified 39 eligible studies. Article selection was conducted using the Rayyan platform, risk of bias was assessed with the Cochrane ROB 2 tool, and results were visualized with ROBVIS. Bibliometric networks were constructed using VOSviewer. Due to data heterogeneity, a meta-analysis was not performed; therefore, results were described and presented graphically. Results: The most commonly used microorganisms belonged to the Lactobacillaceae and Bifidobacteriaceae families, with heat inactivation as the predominant method. Postbiotics exert multifaceted anti-inflammatory effects by modulating cytokine expression, influencing immune cell signaling pathways, and strengthening epithelial barrier integrity. They regulate immune mechanisms such as the Th1/Th2 and Treg/Th17 balance, indicating their potential in treating inflammatory bowel diseases, autoimmune diseases, and metabolic syndrome. However, the heterogeneity of studies, their limitations, and risk of bias require cautious interpretation. Conclusions: Future research should focus on standardizing postbiotic preparations, conducting long-term clinical trials, and analyzing synergistic effects of different strains. Postbiotics offer a promising approach to managing inflammation, with potential applications in functional foods and nutraceuticals.