This review summarizes the mechanistic and therapeutic relevance of Signal Transducer and Activator of Transcription 3 (STAT3) in systemic lupus erythematosus (SLE) and lupus nephritis (LN), with an emphasis on how structural information can inform drug development. STAT3 integrates cytokine- and growth factor-driven JAK-STAT signaling, supports pathological T cell differentiation, B cell activation, and renal inflammation, and has therefore emerged as a potential therapeutic node in lupus. Curr