Peter Moon may refer to:

• Sir Peter Moon (diplomat) (1928–1991), British high commissioner and ambassador
• Peter Moon (comedian) (born 1953), Australian comedian
• Peter Moon, author of books relating to the postulated Montauk Project
• Peter Moon (musician) (1944–2018), Hawaiian musician
• Sir Peter Moon (born 1942), 5th Baronet of Portman Square

• Lettish language
• Lettish Social Democratic Labour Party
• Lettland
• L. Ettmuller
• Lettomanopello
• Letton
• Letton Hall
• Lettopalena
• Lettow
• Lettowianthus
• Lettowianthus stellatus
• Lettre de marque
• Lettres de guerre
• Lettres de marque
• Lettres de Mon Moulin
• Lettres Provinciales
• Lettre Ulysses Award
• Lettrist International
• Lett's Brewery
• Letts nitrile synthesis
• Lettsomia nervosa
• Letts, Son & Co.
• Lettsworth (LA)
• Lettsworth, Louisiana
• Lettuce big vein virus