Morinaga (written: 森永) is a Japanese surname. Notable people with the surname include:
- Ai Morinaga, Japanese manga artist
- Chitose Morinaga (森永 千才), Japanese voice actress
- Masaki Morinaga, Japanese long jumper
- Mayumi Morinaga (森永真由美; born 1981), Japanese singer
- Milk Morinaga, Japanese manga artist
- Sōkō Morinaga, Rinzai Zen roshi
- Taku Morinaga (森永 卓; born 1995), Japanese footballer
- Takuro Morinaga (森永卓郎; 1957–2025), Japanese economist and academic
See also
- Prince Morinaga, murdered by Ashikaga Tadayoshi during the Kemmu Restoration
- Morinaga & Company, a Japanese confectionery company
- Morinaga Milk Industry, a Japanese milk products company