MegaFon (Russian: МегаФон) is the second largest mobile phone operator and the third largest telecommunications company in Russia, headquartered in Moscow. As of 2024, the company serves 77.26 million subscribers across Russia and Tajikistan. MegaFon operates across 83 federal subjects of Russia, Tajikistan and South Ossetia.

In 2002, the company changed its name from North-West GSM to MegaFon when it acquired several regional companies, becoming the first GSM company in Russia to cover all its territory. The name "MegaFon" in Russian is spelled and pronounced exactly like the Russian word for megaphone; other connotations are mega- as "big" and fon as "telephone".

June 17, 1993, was the registration date of North–West GSM CJSC (Saint Petersburg). Alexander Malyshev became the first General Director of the company. The major international investors included Scandinavian companies Sonera (Finland), Telia International AB (Sweden) and Telenor Invest AS (Norway). Telecommunication equipment was supplied by Nokia.

1994 – launch of commercial operation of GSM (2G) network, the first in Russia.

1999 – number of the company's subscribers became over 100,000. By that time the network of the North-West GSM had completely covered Saint Petersburg and Leningrad region, it was also actively expanding in the northern areas of the Russian North-West.

July 1999 – North-West GSM was the first Russian operator that signed roaming agreements with all countries in Europe. The same year, for the first time ever in Russia, mobile communication started to operate in Saint Petersburg metro, and the operator's spectrum of value-added services included WAP-access to the Internet.

2000 – shareholders of the company adopted a new strategy that was targeted at the mass market.

November 2001 – number of North-West GSM subscribers exceeded 500,000.