No. Gautam Swami is not a Tirthankar. He is the chief disciple (Ganadhar) of Mahavira, one of the 11 or 12 Ganadharas who were the primary Jain scriptures’ custodians. In both Digambar and Shwetambar traditions, Gautam Swami is regarded as a revered Jain monk and a senior disciple of Mahavira, not as a Tirthankar.