William Senior may refer to:

• William Senior (journalist), 1837–1920, Anglo-Australian journalist
• William Senior (politician), 1850–1926, Australian politician
• William Senior (historian), 1862–1937, English legal historian
• William Hirst Senior CB FRSE (1904-1984) British agriculturalist

• Operation Harekate Yolo
• Operation Harekate Yolo II
• Operation Harling
• Operation Harmony
• Operation HARMONY
• Operation Harpoon (2002)
• Operation Harpoon (disambiguation)
• Operation Hartmut
• Operation Harvest Festival
• Operation Haudegen
• Operation Have Horn
• Operation Haven
• Operation Hawthorn
• Operation Heads
• Operation Headstart
• Operation Head Start
• Operation Heaven
• Operation Heavenly
• Operation Hedgerow
• Operation Helios
• Operation Hemorrhage
• Operation Herbstgewitter II
• Operation Herrick IV
• Operation Herrick IX
• Operation herrick order of battle