Walter Trelawny was the son and heir of John Trelawny and wife Florence Courtenay. He married Isabel Towse, daughter of John Towse of Taunton, in Somersetshire. There were two known children, John and Richard. He died in 1518.

Catherine, Countess of Devon, in c. 1510 [1 Henry VIII], granted him the Constableship and Bailiwick of Honour and the hundred of Plimpton for life.

The Visitations of Cornwall state that he was "aged 30 and more" at the time of his father's death in 1513. From this, we know that he was born before 1483.

Children of Walter Trelawny and wife Isabel Towse:

• John Trelawny, who married (1) Margery Lamelion, heiress of Thomas Lamelion, and had one son. He married (2) Lora Trecarrel and had one son, also named John.
• Richard Trelawny, who died without heirs.

Links to additional material:

• The Baronetage of England, or, The history of the English baronets, and such Baronets of Scotland as are of English Families, by Rev. William Betham, published 1801 [available as Google e-Book]
• The English Baronetage: Containing a Genealogical and Historical Account of All the English Barnonets Now Existing: Their Descents, Marriages and Issues, Volume 2, By Arthur Collins, published 1741 [available as Google e-Book]
• The visitations of Cornwall: comprising the Heralds' visitations of 1530, 1573 & 1620, John Lambrick Vivian›, College of Arms, published 1887 [available as Google e-Book]