Robert Tjian (Chinese: 錢澤南; pinyin: Qián Zénán; born 1949) is a Hong Kong-born American biochemist best known for his work on eukaryotic transcription.
He is currently professor of biochemistry and molecular biology at the University of California, Berkeley and an Investigator of the Howard Hughes Medical Institute (HHMI).
His father Tjian Tze-Ning (Qian Zining; 錢子寧), a native of Shaoxing, Zhejiang, was a famous capitalist in Shanghai and pioneer of China's modern paper industry.
He was a postdoctoral fellow at Cold Spring Harbor Laboratory with James D. Watson for three years before returning to the University of California in 1979 when he was appointed assistant professor of biochemistry.
In 1978, Tjian found the first protein of a virus which can regulate gene expression in mammalian cells, the SV40 large T antigen.