Yoshinaga is both a Japanese surname and a masculine Japanese given name. Notable people with the name include:
Ōuchi Yoshinaga (1532–1557), 16th century Kyushu warrior
Asano Yoshinaga (1576–1613), Japanese samurai and feudal lord of the late Sengoku and early Edo period
Fumi Yoshinaga (born 1971), Japanese manga artist, known for her shōjo and shōnen-ai works
Matsudaira Yoshinaga (1828–1890), the 14th head of Fukui Domain during the Late Tokugawa shogunate and politician of the Meiji era
Sayuri Yoshinaga (born 1945), Japanese actress
Yoshinaga Fujita, award winning novelist and screenwriter from Japan
Fictional characters:
Miyuki Yoshinaga, human guise of the Orchid Undead from Kamen Rider Blade