Signal transducer and activator of transcription 3 (STAT3), a member of the STAT protein family, serves as both a signal transducer and a transcription factor. Previous studies have highlighted its pivotal roles in regulating cell proliferation, differentiation, apoptosis, as well as immune and inflammatory responses. Consequently, targeting STAT3 has emerged as a promising therapeutic strategy for addressing related diseases. This review offers a comprehensive summary of the progress in discovering STAT3 inhibitors, with a focus on their structural diversity and structure-activity relationships as presented in patent literature from 2022 to the present. Over the past decades, significant progress has transformed STAT3 into a target of interest for drug development. Despite these advances, no STAT3-targeting drugs have successfully progressed through late-phase clinical trials, largely due to challenges such as limited selectivity and undesirable side effects. These obstacles highlight the inherent complexity of developing safe and effective STAT3 inhibitors. Nevertheless, STAT3 remains a highly promising therapeutic target, and ongoing advancements in this field hold the potential to unlock novel strategies for addressing STAT3-related diseases.