Usnu may refer to:

• Ushnu or usnu, a pyramid-shaped, terraced structure that was used by the Incas
• Usnu, Ayacucho, an archaeological site in the Ayacucho Region, Peru
• Usnu, Huánuco, an archaeological site in the Huánuco Region, Peru

• Eastern long-beaked echidna
• Eastern long-billed lark
• Eastern long-eared bat
• Eastern long-fingered bat
• Eastern Long Island, New York
• Eastern long-necked turtle
• Eastern longnose spurdog
• Eastern Long-tailed Hermit
• Eastern long-tailed hermit
• Eastern Los Angeles
• Eastern Los Angeles (region)
• Eastern Lowland gorilla
• Eastern lowland olingo
• Eastern Lubber Grasshopper
• Eastern Lunda
• Eastern Macedonia
• Eastern Maine Railway (1994)
• Eastern Main Road
• Eastern Malaysia
• Eastern Mallee
• Eastern many-horned adder
• Eastern march
• Eastern Marches
• Eastern marches
• Eastern Marching Band Association