Thomas Samuel Grace (16 February 1815 – 30 April 1879) was an English Anglican missionary in New Zealand. He was born in Liverpool, Lancashire, England on 16 February 1815.
He was a member of the Church Missionary Society and was stationed at Taupo from 1850. In 1865 the Pai Mārire ransacked his house. Rev Grace, who had fled from Taupo to Opotiki, was caught up in the Völkner Incident. He was arrested and put on trial by the Pai Mārire party. He was rescued from captivity two weeks later by a British man-of-war, HMS Eclipse, after an attempt by the Pai Mārire to exchange him for Tauranga chief Hori Tupaea, who was in prison. In the 1870s he rebuilt the mission station at Taupo.
His son Lawrence Marshall Grace was Member of Parliament for Tauranga in the 1880s.