Moscow University is established (12 January 1755 O.S.).

Moscow State University (MSU), officially M. V. Lomonosov Moscow State University, is a public research university in Moscow, Russia. The university includes 15 research institutes, 43 faculties, more than 300 departments, and six branches. Alumni of the university include past leaders of the Soviet Union and other governments. As of 2019, 13 Nobel laureates, six Fields Medal winners, and one Turing Award winner were affiliated with the university.

Old Style (O.S.) and New Style (N.S.) indicate dating systems before and after a calendar change, respectively. Usually, they refer to the change from the Julian calendar to the Gregorian calendar as enacted in various European countries between 1582 and 1923.

January 23 is the 23rd day of the year in the Gregorian calendar; 342 days remain until the end of the year.