Born in Antigua to a wealthy plantation owner, Thomas Oliver graduated from Harvard College in 1753.
In 1760 he married Elizabeth Vassall, who was from another family of West Indies plantation owners that had settled in Massachusetts.
On September 2, 1774, Oliver saw a crowd of four thousand angry citizens entering Cambridge and traveled to Boston to advise General Thomas Gage not to send troops against them.
On his return, the crowd, defying the advice of their political leaders, surrounded Oliver's house and forced him to sign a resignation.
The British government continued to recognize him as lieutenant governor of Massachusetts and pay his salary until he died.