Born in Canterbury, Kent, the son of a barrister, Tomlin was educated at Harrow School and New College, Oxford, where he obtained a first-class degree in jurisprudence and second-class honours in the BCL.

He took silk in 1913 and was elected a bencher of Lincoln's Inn in 1928[1] In 1923, Tomlin was appointed as a judge to the Chancery Division of the High Court and received the customary knighthood.

[1] On 11 February 1929, he was appointed Lord of Appeal in Ordinary (without first serving on the Court of Appeal) and was created a life peer with the title Baron Tomlin, of Ash in the County of Kent, and was sworn into the Privy Council.

If he succeeds in ordering them so as to secure this result, then, however unappreciative the Commissioners of Inland Revenue or his fellow tax-payers may be of his ingenuity, he cannot be compelled to pay an increased tax.

[1] He married Marion Olivia Waterfield in 1893; they had two daughters and three sons, the youngest of whom was the sculptor Stephen Tomlin.