Khariton Laptev was born in a gentry family, Laptev family which was a branch of the Lopukhin family, in the village of Pokarevo near Velikiye Luki (in the southern part of today's Pskov Oblast), just a year before his cousin Dmitry Laptev was born in the nearby village of Bolotovo.
Khariton Laptev started his career in the Russian Navy as a cadet in 1718.
In 1739–1742, Khariton Laptev led one of the parties of the Second Kamchatka expedition.
Together with Semion Chelyuskin, N. Chekin, and G. Medvedev, Laptev described the Taimyr Peninsula from the mouth of the Khatanga River to the mouth of the Pyasina river and discovered a few of the islands in the area.
After the expedition, he participated in the creation of the "General Map of the Siberian and Kamchatka Coast", and continued his military service in the Baltic Fleet.