Mikhail Moiseyevich Botvinnik (Russian: Михаи́л Моисе́евич Ботви́нник; IPA: [mʲɪxɐˈil məɪˈsʲejɪvʲɪdʑ‿bɐˈtvʲinʲːɪk]; August 17 [O.S. August 4] 1911 – May 5, 1995) was a Soviet and Russian chess grandmaster who held five world titles in three different reigns. The sixth World Chess Champion, he also worked as an electrical engineer and computer scientist and was a pioneer in computer chess, the last of which he was awarded an honorary mathematics degree for.

Botvinnik was the first world-class player to develop within the Soviet Union. He played a major role in the organization of chess, making a significant contribution to the design of the World Chess Championship system after World War II and becoming a leading member of the coaching system that enabled the Soviet Union to dominate top-class chess during that time. His pupils include World Champions Anatoly Karpov, Garry Kasparov and Vladimir Kramnik. He is often described as the patriarch of the Soviet chess school and is revered for his analytical approach to chess.

Botvinnik was born on August 17, 1911, in what was then Kuokkala, Vyborg Governorate, Grand Duchy of Finland, now the district of Repino in Saint Petersburg. His parents were Russian Jews; his father, Moisei Botvinnik (1878–1931), was a dental technician and his mother, Shifra (Serafima) Rabinovich (1876–1952), a dentist, which allowed the family to live outside the Pale of Settlement, to which most Jews in the Russian Empire were restricted at the time. As a result, Botvinnik grew up in Saint Petersburg's Nevsky Prospect. His father forbade speaking Yiddish at home, and Mikhail and his older brother Isaak "Issy" attended Soviet schools. Botvinnik later recounted, "I was asked once, "What do you consider yourself to be from the point of view of nationality?" My reply was, "Yes, my position is 'complicated'. I am a Jew by blood, a Russian by culture, Soviet by upbringing."" On his religious views, he called himself an atheist.

In 1920, his mother became ill and his father left the family, but maintained contact with the children, even after his second marriage to a Russian woman. At about the same time, Botvinnik started reading newspapers, and became a committed communist.

In autumn 1923, at the age of twelve, Botvinnik was taught chess by a school friend of his older brother, using a home-made set, and instantly fell in love with the game. He finished in mid-table in the school championship, sought advice from another of his brother's friends, and concluded that for him it was better to think out "concrete concepts" and then derive general principles from these – and went on to beat his brother's friend quite easily. In winter 1924, Botvinnik won his school's championship, and exaggerated his age by three years in order to become a member of the Petrograd Chess Assembly – to which its president turned a blind eye. Botvinnik won his first two tournaments organized by the Assembly. Shortly afterwards, Nikolai Krylenko, a devoted chess player and leading member of the Soviet legal system who later organized Joseph Stalin's show trials, began building a huge nationwide chess organization, and the Assembly was replaced by a club in the city's Palace of Labour.

To test the strength of Soviet chess masters, Krylenko organized the Moscow 1925 chess tournament. On a rest day during the event, world champion José Raúl Capablanca gave a simultaneous exhibition in Leningrad. Botvinnik was selected as one of his opponents, and won his game. In 1926, he reached the final stage of the Leningrad championship. Later that year, he was selected for Leningrad's team in a match against Stockholm, held in Sweden, and scored +1=1 against the future grandmaster Gösta Stoltz. On his return, he entertained his schoolmates with a vivid account of the rough sea journey back to Russia. Botvinnik was commissioned to annotate two games from the match, and the fact that his analyses were to be published made him aware of the need for objectivity. In December 1926, he became a candidate member of his school's Komsomol branch. Around this time his mother became concerned about his poor physique, and as a result he started a programme of daily exercise, which he maintained for most of his life.

When Botvinnik finished the school curriculum, he was below the minimum age for the entrance examinations for higher education. While waiting, he qualified for his first USSR Championship final stage in 1927 as the youngest player ever at that time, tied for fifth and sixth places and gained the title of master. He wanted to study Electrical Technology at the Leningrad Polytechnical Institute and passed the entrance examination; however, there was a persistent excess of applications for this course and the Proletstud, which controlled admissions, had a policy of admitting only children of engineers and industrial workers. After an appeal by a local chess official, he was admitted in 1928 to Leningrad University's Mathematics Department. In January 1929, Botvinnik played for Leningrad in the student team chess championship against Moscow. Leningrad won and the team manager, who was also deputy chairman of the Proletstud, secured Botvinnik a transfer to the Polytechnic's Electromechanical Department, where he was one of only four students who entered straight from school. As a result, he had to do a whole year's work in five months, and failed one of the examinations. Early in the same year he placed joint third in the semi-final stage of the USSR Championship, and thus failed to reach the final stage.

His early progress was fairly rapid, mostly under the training of Soviet Master and coach Abram Model, in Leningrad; Model taught Botvinnik the Winawer Variation of the French Defence, which was then regarded as inferior for Black, but Botvinnik analysed it more deeply and played this variation with great success.