Matsunaga (written: ) is a Japanese surname. Notable people with the surname include:
- Daniel Matsunaga, Japanese-Brazilian model, actor and football player currently based in the Philippines
- Enzo Matsunaga, author
- Futoshi Matsunaga, Japanese serial killer
- Hikaru Matsunaga, Japanese legislator and finance minister
- Hisahide Matsunaga, daimyō of the Matsunaga clan in the Sengoku period
- Mari Matsunaga, founder of i-mode mobile service and Seiko Epson board director
- Masatoshi Matsunaga, Imperial Army Lieutenant General and Baron, Second Class
- , Japanese professional wrestler
- Sadaichi Matsunaga, Imperial Japanese Navy Vice Admiral
- , Japanese sport wrestler
- Spark Matsunaga, United States Senator from Hawaii
- , Japanese footballer
- Toh Matsunaga, Chairman of the 45th House of Representative
- , Japanese professional wrestler
- Yoshisuke Matsunaga, Japanese mathematician of the 18th century
- , Japanese voice actress
Fictional characters
- Baron Tsuneyoshi Matsunaga, Mameha's danna in Memoirs of a Geisha
- Mikage & Tomomi Matsunaga, the twin main characters from the manga series Miracle Girls