He was the second son of politician Henry Dawkins, who owned slave plantations in the British colony of Jamaica, and his wife Lady Juliana Colyear.

A year later, his second cousin Richard Pennant, 1st Baron Penrhyn died and left his estate to Dawkins, who changed his surname to Dawkins-Pennant to inherit it.

[2][3] In 1814, Dawkins-Pennant ran in a parliamentary by-election for the constituency of Newark after Sir Stapleton Cotton left the seat, and was elected to the House of Commons of the United Kingdom on 19 May.

Dawkins-Pennant represented Newark until the 1818 United Kingdom general election, when he was replaced by Sir William Henry Clinton.

[7] They had two children, of which eldest son George Sholto Gordon Douglas-Pennant succeeded his father in 1886 as the 2nd Baron Penrhyn.