Leach married twice. His first marriage was in 1597 to Elizabeth Borrough (died 1599), daughter of Walter Borrough of Exeter. By Elizabeth he had two sons: Simon (born 1598), who died young, and Sir Walter Leach (1599 – before 1637), second son and heir apparent, who predeceased his father. Walter was knighted by King Charles I at the
Palace of Whitehall on 3 December 1626. In 1626 he married Sara Napier, a daughter of
Sir Robert Napier, 1st Baronet (1560–1637), of
Luton Hoo in
Bedfordshire. Leach's second wife was Katherine Turbervile (died before 1637), the eldest daughter of Nicholas Turbervile of Crediton by his wife Charity Prideaux, a daughter of Richard Prideaux (died 1603) of
Thuborough,
Sutcombe, Devon. By Katherine he had seven further children: • Simon (born 1601), third son. He died childless. • George (1602-pre-1637), fourth son, whose wife, Margaret, survived him and remarried to Bevil Prideaux (a grandson of Richard Prideaux (died 1603) of Thuborough) of
Spencer Combe near Crediton. Bevil Prideaux sold Spencer Combe to Sir Simon Leach (died 1638). • Nicholas (died 1646), fifth son, of Newton St Petrock, who married Grace Mallock, daughter of Roger Mallock of Exeter. • Katherine, who married as her second husband Thomas Giffard (1607–1648) of
Halsbury,
Parkham, Devon. • Elizabeth, Rebecka, and Anne. ==Death and monument==