St. Thomas Church was built long before electricity was available, and thus, it relied on natural light for illumination. The north and the south walls are divided by rows of tall windows, which allow sunlight and air circulation when the church is used for service on Sundays. Over the years, some of the windows got covered in stained glass.
Memorial to Richard Cobbe, the East India Company chaplain who "stirred up his countrymen to complete the church." Though the foundation stone was laid in 1676, construction got delayed due to a lack of funds, raids by hostile enemies, and repeated plague outbreaks. The church was consecrated for divine worship on Christmas Day, 1718.
The chancel gate of St. Thomas Church was presented in 1865. Painted in black and gold, the wrought iron gate is intricately designed in a geometric pattern with decorative floral motifs. The detail is typical of Gothic tracery and known as patera, with the use of flowers, flowing creepers, and leaves. The separate floral elements are riveted to the gate.
Commemorative plaques were placed on the pew, marking the visit by Mother Teresa on 8 January 1983. A second plaque was added to Mother Teresa's canonization at the Vatican City on 4 September 2016 by Pope Francis. Henceforth, Mother Teresa was known as Saint Teresa of Calcutta.
Stained glass panel with winged figure of the Archangel Gabriel carrying lilies. Gabriel is mentioned in the Hebrew Bible, the New Testament, and the Quran. Many Christian traditions – including Catholicism, Eastern Orthodoxy, Lutheranism, and Anglicanism — revere Gabriel as a saint.
Memorial plaque erected in memory of Henry Curwen (1845–1892), who died on 22nd Feb 1892, on board the P and O ship SS Ravenna, three days out of Mumbai. The vessel didn't return to port, and the body was buried at sea. Henry Curwen was born at Workington Hall in Cumbria and arrived in India in 1876 to work as a journalist. In 1880, he became the editor of the Times of India.