Longstreth is a surname. Notable people with the surname include:

• Alec Longstreth (born 1979), comics creator and illustrator
• Bevis Longstreth, retired lawyer and former Commissioner of the United States Securities and Exchange Commission
• David Longstreth (born 1981), American singer and musician
• Jake Longstreth (born 1977), American painter and radio personality
• Richard Longstreth (born 1946), architectural historian and a professor at George Washington University
• Thacher Longstreth (1920–2003), Republican member of the Philadelphia City Council

• Millana, Guadalajara
• Millana, Spain
• Milland
• Millanes
• Millanes, Cáceres
• Millanes, Spain
• Millant, Jean Jacques
• Millar
• Millar Addition
• Millard
• Millard Airport
• Millard Airport (Nebraska)
• Millard Complex fire
• Millard Elementary School
• Millard Erickson
• Millard Fillmore House
• Millard Fuller
• Millard (given name)
• Millardia
• Millardia gleadowi
• Millardia kathleenae
• Millardia kondana
• Millardia meltada
• Millard J. Monkey
• Millard Johnson (Macross)