Morinaga (written: ) is a Japanese surname. Notable people with the surname include:
Ai Morinaga, Japanese manga artist , Japanese voice actress Masaki Morinaga, Japanese long jumper , Japanese singer Milk Morinaga, Japanese manga artist Sōkō Morinaga, Rinzai Zen roshi , Japanese footballer , 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