Contributions

Tan contributed generously to charity and became a renowned philanthropist amongst the Chinese. He was known to provide burial costs for the Chinese poor. His most famous gesture was the donation of Spanish $7,000 to the building of the Chinese Pauper's Hospital (later to be named after him , the Tan Tock Seng Hospital or TTSH) in 1844 at Pearl's Hill. The building was designed by John Turnbull Thomson and it was opened in 1849. The hospital was later shifted to Tan Tock Seng Road because the building at Pearl's Hill was too small to cater to enough patients and it was too old.

He was also a founder of the Taoist Thian Hock Keng Temple at Telok Ayer Street, Singapore's oldest temple, which had been the centre of worship for the Fujian Chinese. Tan Tock Seng was the first Asian to be made a Justice of the Peace by the Governor Butterworth. His role in helping the early Chinese immigrants settle disputes earned him the title "Captain of the Chinese."