Judge Johnston my refer to:
Iain D. Johnston (born 1965), judge of the United States District Court for the Northern District of Illinois Thomas E. Johnston (born 1967), judge of the United States District Court for the Southern District of West Virginia Henry Johnston, Lord Johnston (1844–1931), Scottish judge
See also Justice Johnston (disambiguation) Edward Huggins Johnstone (1922–2013), judge of the United States District Court for the Western District of Kentucky