Mowbray married, by papal dispensation dated 25 March 1349,[5] Elizabeth de Segrave (born 25 October 1338 at Croxton Abbey),[5] suo jure Lady Segrave, daughter and heiress of John de Segrave, 4th Baron Segrave (d.1353),[3] by Margaret, daughter and heiress of Thomas of Brotherton, son of Edward I.[12]
They had two sons and three daughters:[12]
John de Mowbray, 1st Earl of Nottingham (1 August 1365 – before 12 February 1383), who died unmarried, and was buried at the Whitefriars, London.[13]
Thomas de Mowbray, 1st Duke of Norfolk.[14]
Eleanor Mowbray (born before 25 May 1364),[5] who married John de Welles, 5th Baron Welles.[13][15]
Margaret Mowbray (d. before 11 July 1401), who married, by licence dated 1 July 1369, Sir Reginald Lucy (d. 9 November 1437) of Woodcroft in Luton, Bedfordshire.[16]
Joan Mowbray, who married firstly Sir Thomas Grey (1359 – 26 November or 3 December 1400) of Heaton near Norham, Northumberland, son of the chronicler Sir Thomas Grey, and secondly Sir Thomas Tunstall of Thurland in Tunstall, Lancashire.[17][13]