Bolshoy Begichev (Russian: Большой Бегичев, lit.

'Big Begichev') is an island in the Laptev Sea, in the Sakha Republic, Russia.

North of Bolshoy Begichev lies small Preobrazheniya Island.

This elongated granitic island was useful as a landmark for ships plying the Northern Sea Route in the past.

It was added to the list of International 518 kHz NAVTEX stations in GMDSS/Circ.8/Corr.6 (25 October 2002), reiterated in GMDSS/Circ.8/Corr.8 (25 July 2003), and removed in GMDSS/Circ.8/Corr.9 (29 September 2003).