After being apprenticed in London, he became a freeman of the Worshipful Company of Grocers between 1537 and 1539, and married Alice (1492/93–1578), daughter of Bevis Lea of Enfield in Staffordshire in 1540.
As a successful merchant, in 1566 he purchased a house "with a very fair forefront"[6] in Lombard Street, formerly the home of Sir Martin Bowes, which was also his place of business[7] Sir Thomas refers to "my mansion house" in his will,[4] and apparently it was a large important building, having a garden to the rear and a lodge at the entry to a courtyard.
[10] Sir Thomas, known as "Rich Ramsey" was active in charitable work, and was Governor of St Bartholomew's Hospital from 1559 to 1560 until 1560–61.
"The Trewe Inventorye of all the moveable goodes, househoulde stuffe and plate, which were latelie the goodes and chattels of Sir Thomas Ramsey…" dated 1590, lists in detail and room by room, the furnishings and contents of the house, with the estimated value of each item or set of items, in pounds, shillings and pence.
[4] An indication of Ramsey's importance and influence is revealed in his will, where his executors are reminded that a loan of £550 to Robert, Earl of Leicester (Queen Elizabeth's favourite), was due in January 1587.
Sir Thomas was buried in his parish church St Mary Woolnoth (on the south side of Lombard Street), with a monument at the east end of the chancel.