Dr. Man Mohan Singh Ahuja (M.M.S. Ahuja; 16 August 1929 – 12 July 1998) was a pioneering Indian physician and endocrinologist. He played a foundational role in establishing modern endocrinology and diabetes care in India and received the Padma Shri in 1991.

Born in 1929 in Multan (then in British India, now Pakistan), he began medical studies in Lahore but moved to India after Partition. He graduated from Madras Medical College in 1952 (some records note 1950). He then went to the United Kingdom, obtained his MRCP (London) in 1956, and completed residency at Hammersmith Hospital.

In 1958 he joined the All India Institute of Medical Sciences (AIIMS), New Delhi, as a Registrar in the Department of Medicine under the legendary Prof. K.L. Wig. He rose steadily, becoming Associate Professor and later Head of the Department of Medicine in 1969. When the independent Department of Endocrinology and Metabolism was created in 1982, he became its first Head and served until 1989. He was also Dean of AIIMS in 1988–89.

Dr. Ahuja was instrumental in founding the Research Society for the Study of Diabetes in India (RSSDI) in 1972 and the Hormone Foundation, India. He served as the founding editor of the International Journal of Diabetes in Developing Countries and edited the “Progress in Medicine” series. He trained generations of endocrinologists and diabetologists who later became leaders in the field, and served on expert committees of the Indian Council of Medical Research.

After retiring from AIIMS in 1990 he continued as a senior consultant at the Sitaram Bhartia Institute until his death. He received the Dr. B.C. Roy Award for medical research in 1982 and the Padma Shri in 1991.

Colleagues remembered him as an outstanding physician, teacher, researcher and administrator. “Diabetes care in India needed its own identity,” he often told younger doctors. “We must study it in our own patients and build knowledge that serves our people.”

Dr. Man Mohan Singh Ahuja passed away on 12 July 1998 in New Delhi. He is remembered as one of the architects of endocrinology and diabetes research in India.