Reactive arthritis is an extremely rare spondyloarthritis that affects the peripheral joints and spine, resulting in common symptoms such as arthritis, urethritis, conjunctivitis, and mucocutaneous lesions. On rare occasions, oral lesions such as circinate erosions on the hard and soft palate, gums, tongue, and cheeks may occur. Reactive arthritis may develop during or after genitourinary or gastrointestinal bacterial infections such as Shigella, Salmonella, Yersinia, and Chlamydia. A 36-year-old man presented with circinate balanitis, urethral discharge, oligoarthralgia, conjunctivitis, lymphadenopathy, pharyngitis, and erythematous lesions on the palate. Culture examination showed presence of Neisseria gonorrhoeae and antibiotic treatment resulted in improvement of conjunctivitis and the lesions on the penis. However, severe oligoarthralgia, palatal erosions that increased in severity and size, and depilated areas on the tongue were observed. The definitive diagnosis was reactive arthritis. The prevalence of sexually transmitted infections is increasing, highlighting the need to increase awareness of associated risks such as reactive arthritis. Moreover, consideration of non-specific oral manifestations in a systemic context may aid in effective diagnosis and treatment, suggesting the need for multidisciplinary teams.