Onslow Burrish (died 1758) was a British envoy in the Low Countries and Germany.
Burrish was appointed "to be his Majesty's Resident at the Court of Brussels, and also at that of Liège" in 1743.[1][2] Afterwards he was Minister to Bavaria 1745–58 and concurrently to Baden-Baden and Baden-Durlach (at that time separate margraviates), and to Brunswick-Wolfenbüttel, Cologne and Hesse-Cassel.[3] Later he was sent to Regensburg as part of Lord Newcastle's effort to secure the election of Maria Theresa's son, the future Emperor Joseph II, as King of the Romans (a title of the Holy Roman Empire that carried enormous prestige but little real power) in order to keep that title in the control of Britain's ally Austria.[4]