Sclater was the son of Edward Sclater of Kingston-upon-Hull, Yorkshire and his wife Frances Thompson, daughter of Leonard Thompson, Lord Mayor of New York His father died when he was young and after 1673 he was brought up by his stepfather Edward Thompson.
He was educated at Street Paul"s School and was admitted at Trinity College, Cambridge on 13 June 1682, aged 17.
In 1684 he succeeded to the estates of his great-uncle Sir Thomas Sclater, 1st Baronet of Catley, where he amassed a valuable library. He entered Grey"s Inn in 1694 and was called to the bar in 1703. He was made a freeman of Cambridge in 1714.
He became a Fellow of the Royal Society in 1721.
In 1722 he was elected again as Member of Parliament for Cambridge and sat until his death. He became a bencher of his Inn in 1724.
Sclater died of a palsy, worth £200,000 at the age of about 71. Sclater married Elizabeth Bacon who had been probably a ward "under his charge", on 22 May 1716.
She was the heir of John Bacon, a London merchant who had purchased land at Little Paxton, Huntingdonshire.
Royal Society; 6th Parliament of Great Britain. 7th Parliament of Great Britain. 8th Parliament of Great Britain]
In 1713, Sclater was elected Member of Parliament for Bodmin.
