The Dominion of Newfoundland had, like every other British Dominion, had a High Commissioner to London, starting in 1918. It stopped in 1934, when Britain started talking directly to the Commission of Government.
The Newfoundland High Commissioners to the UK were:
Sir Edgar Rennie Bowring KCMG (1st time), 1918-22.
Lt.-Col. Thomas Nangle CF, 1923-24.
Capt. Victor Gordon CMG MC, 1924-28.
Sir John R. Bennett KBE, 1928.
Daniel James Davies CBE, 1928-32.
Sir Edgar Rennie Bowring KCMG (2nd time), 1933-34.