Bernhard Karlgren (1889 - 1978) was a Swedish sinologist. His full name was Klas Bernhard Johannes Karlgren, and his Chinese penname is 高本漢 (Gao Benhan).

Karlgren was first to use European-style principles of historical linguistics to study the Chinese language, and reconstructed the phonetics of what is now called Middle Chinese, as well as the phonetics of Old Chinese. He also suggested that at the very earliest stage recoverable, the personal pronouns were inflected for case.

His most influential works include:

• Études sur la phonologie chinoise. 1915-1926.
• Analytic Dictionary of Chinese and Sino-Japanese 1923.
• Grammata Serica Recensa. 1957

Although his pioneering work was important in many ways, much of it has been made outdated by advances in both theory and application, as well as the greater availability of relevant data.