H19 or H-19 may refer to:

• H19 (gene), a maternally-transmitted human gene
• British NVC community H19, a type of heath community in the British National Vegetation Classification
• Heathkit H19, a serial terminal used with the Heathkit H8 microcomputer
• Highway H19 (Ukraine)
• HMS H19, an H-class submarine ordered by but not commissioned into the Royal Navy
• HMS Harvester (H19), a Royal Navy H-class destroyer
• London Buses route H19, a public transportation route in London, England
• Sikorsky H-19, an American helicopter