LRN may refer to:

• Laboratory Response Network, a collaborative effort of the U.S. Centers for Disease Control and Prevention and the Association of Public Health Laboratories
• Land Rights News, the longest-running Aboriginal Australian newspaper, published by the Central and Northern Land Councils
• Lateral reticular nucleus, a nucleus of the medulla oblongata involved with co-ordinating baroreceptor signals to control arterial blood pressure
• Lead round nose, a type of bullet
• Legislative route number, a designation for a highway defined by laws passed in a state legislature
• Location Routing Number, a ten digit phone number used to route phone calls between two telephone exchanges
• LORAN, a terrestrial radio navigation system originally known as LRN for Loomis Radio Navigation
• LRN (company), an ethics compliance and education company
• Luminous red nova, a stellar explosion thought to be caused by the merger of two stars