Sir Thomas Hoo, son of Sir William and Dame Alice, was born around 1370, and married first, c. 1395, Eleanor de Felton (born c. 1361). She was the widow of Sir Robert de Ufford, "de jure" Lord Clavering (died c. 1393)), and was the youngest of three daughters of Sir Thomas de Felton, Seneschal of Aquitaine, of Litcham, Norfolk (died 1381) and his wife Joan (Walkfare). The son of Sir Thomas Hoo and Eleanor de Felton was the future Lord Hoo and Hastings, born c. 1396, who had three half-sisters on the Ufford side. His mother Eleanor died on 8 August 1400, and his father remarried to Elizabeth Echyngham (daughter of Sir William Echingham (died 1413–1414) of Etchingham, Sussex), who thus became stepmother to the child Thomas.