Chennai is highly cosmopolitan and secular, with diverse religious communities living in deep-rooted harmony.
- **Hinduism:** The majority faith. The city is dotted with ancient, architecturally magnificent temples like the **Kapaleeshwarar Temple** and the **Parthasarathy Temple** in Triplicane. - **Christianity:** Deep historical roots dating back to St. Thomas the Apostle. Key landmarks include **San Thome Basilica**, **St. Mary's Church** (the oldest Anglican church in India), and Velankanni Church in Besant Nagar. - **Islam:** A significant community centered historically around areas like Triplicane, home to the magnificent 18th-century **Wallajah Mosque** (Big Mosque), and Royapettah. - **Other Faiths:** The city has vibrant Jain communities (particularly in Sowcarpet with beautifully carved Jain temples), as well as Sikh, Buddhist, and Parsi populations.