Sir Thomas Knollys or Knolles (died 1435) was an English businessman in London who was active in both local and national government.

[1][2][3][4] Born about 1350, he was once thought to be descended from the soldier Sir Robert Knollys but modern sources give his father as Richard.

[3][4] Before 1387 he had become a member of the Grocers' Company, which he served as warden and as master, contributing to the building of their new hall in Poultry and to the rebuilding of the guild church of St. Antholin in Watling Street, where he lived.

In addition to his main business interests in goods and properties, he also became a major financier, lending extensively to other businessmen and to the government.

[3][4] In local government, he was an alderman by 1393, Sheriff of London in 1394 and twice served as Lord Mayor in 1399 and in 1410, in his second term being responsible for rebuilding the Guildhall.