Lovett was born at Astwell Castle, Northamptonshire, England.
His father, Thomas Lovett II, was amongst the principal landowners of Northamptonshire in the Commissions of the Peace issued by Edward IV, Richard III and Henry VII, and was High Sheriff of Northamptonshire in 1491.
He married Elizabeth Boteler and with her had eight children, sons Thomas (heir apparent), William, and Nicholas, plus daughters Constance, Margaret, Elizabeth, and Anne.
With this wife, Jane Pinchpole, he had a son, George, and daughters, Elizabeth, Mary, and Bridget.
Thirdly, he married Joan Billing, his cousin, in 1490, and they had one child, Thomas (d. 1510).