The Bolshoy Patom (Russian: Большой Патом - Big Patom), is a river in Irkutsk Oblast, Russia. It is the 11th longest tributary of the Lena with a length of 570 kilometresand a drainage basin area of 28,400 square kilometres.
Bolshoy Patom village is located by the riverbank in its lower course. Tourists visit the Bolshoy Patom river mainly for rafting and kayaking. In the International scale of river difficulty the Bolshoy Patom is a Class III and IV river. There are picturesque white limestone cliffs flanking a number of stretches of the Bolshoy Patom.
