Bidhu Bhushan Ray (also Bidhu Bhusan Ray, Bidhubhusan Ray and B. B. Ray) was an Indian physicist. He was a pioneer in the field of X-ray spectroscopy, and his laboratory was the first of its kind in India. Also notable are his contributions to studies related to scattering of light in the atmosphere. He played a significant role in facilitating contacts between Indian and European scientists. He was elected Fellow, Indian National Science Academy, and held the post of Khaira Professor of Physics at the Rajabazar Science College, University of Calcutta till the time of his death.