Khadg Singh Valdiya (20 March 1937 – 29 September 2020) was an Indian geologist[3] and a former vice chancellor of Kumaon University, internationally recognized for his path-breaking work in the fields of geodynamics and Environmental Science.

His internationally recognized works[9][10] are based on the painstaking mapping of mountainous terrain, traversing thousands of kilometers on foot.

Pant Institute of Himalayan Environment and Development (Katarmal, Almora), and the Department of Geology in Kumaun University (Nainital).

Along with leading teachers and specialists from various disciplines, he has been delivering and organizing lectures on the application of science, the avenues & opportunities for young minds, as well as offering career guidance to pre-university college students.

[14] These include Geology of Kumaon Lesser Himalaya (1980),[15] Aspects of Tectonics: Focus on South-central Asia (1984),[16] Environmental Geology: Indian Context (1987),[17] Dynamic Himalaya (1998),[18] Himalaya: Emergence and Evolution (2001),[19]Kumaun Land and People (2001),[20]Saraswati, the River That Disappeared (2002),[21] The Making of India: Geodynamic Evolution (2010),[22] and Ek Thi Nadi Saraswati (2010, in Hindi).,[1][23] Geography, Peoples and Geodynamics of India in Puranas and Epics: A Geologist's Interpretations (2012),[24] Prehistoric River Saraswati, Western India: Geological Appraisal and Social Aspects (2018),[25] Neotectonism in the Indian Subcontinent: Landscape Evolution (2017)(Co-authored with Jaishri Sanwal)[26] His autobiography "पथरीली पगडंडियों पर" was published by PAHAR [27] in 2015.

In 2017, he wrote a biography of famous environmentalist and Chipko leader Padma Vibhushan Sunderlal Bahuguna named ‘हिमालय में महात्मा गांधी के सिपाही सुंदरलाल बहुगुणा’ [28] published by Sasta Sahitya Mandal.