Sir Thomas Allen, 1st Baronet (c. 1566 – 7 March 1627) was son of John Alen (d. 29 September 1616) of St. Wolstan's, near Celbridge, and Anne, dau of Thomas Dillon of Riverstown.
He was created a Baronet, of St Wolstons in the County of Kildare, in the Baronetage of Ireland on 7 June 1622, for the services rendered by his long-dead great-uncle, Archbishop John Alen, and also a payment to the Crown. He was invested as a Knight on 8 June 1622.
He married, firstly,
He married, secondly,
He died on 7 March 1626/27, without issue, and was buried in Donacomper, Celbridge. His will (dated 1 March 1626) was probated on 18 April 1627. On his death, his baronetcy became extinct.
He should not be confused with Sir Thomas Allen, 1st Baronet, of Totteridge, Middlesex.