He was the sixth son of Sir John Street John, 1st Baronet of Lydiate Tregoze and inherited the baronetcy on the death of his nephew Sir John Street John, 2nd Baronet (c1637–1657), the son and heir of Oliver, the son and heir apparent of Sir John, 1st Baronet.
He was famed for "piety and moral virtues". In 1700, Sir Walter signed a trust deed that led to the formation of a school which later became the Sir Walter Street John"s School of Battersea. Sir Walter died in his 87th year on 3 July 1708, and was buried on 9 July at Battersea.
On his death the baronetcy passed to a grandson Henry Street John who was created a viscount in 1716.
Johanna died three years before Sir Walter. They had thirteen children, but seven of them did not survive to adulthood.
Cavalier Parliament. Habeas Corpus Parliament]
In 1656, Sir Walter was Member of Parliament for Wiltshire (1656–1658 and 1659). Foreign Wootton Bassett (1660–1679).
And again for Wiltshire (1679-1681 and 1690-1695).
