Sir Gonne St Clair Pilcher, MC (19 September 1890 – 3 April 1966) was a British barrister and High Court judge.
During the First World War, he served in France and Belgium, for which he was mentioned in dispatches and was awarded the Military Cross.
He headed the United Kingdom's delegation to the Brussels Diplomatic Conference on International Maritime Conventions in May 1952, September 1958, and May 1961.
In 1918, Pilcher married Janet, elder daughter of Allan Hughes, of Lynch, Allerford, Somerset.
They had a son, killed on active service in 1941, and a daughter, Judith, who married Robin Dunn (later a Lord Justice of Appeal) in 1941.