Nigel Philip Casey is a British diplomat, who has been His Majesty's Ambassador to the Russian Federation since November 2023. He served as the British Ambassador to Bosnia and Herzegovina from September 2011 until 2013, and then as the British High Commissioner to South Africa from April 2017 until April 2021. From May 2021 to 2023, was concurrently the Foreign Office's Director for Afghanistan and as the Prime Minister's Special Representative for Afghanistan and Pakistan.