Mikhalkov was born to Vladimir Alexandrovich Mikhalkov and Olga Mikhailovna (née Glebova). Mikhalkov stemmed from the noble family of Mikhalkovs and had tsarist admirals, governors, and princes among his grandparents. Since the 1930s, he has rivalled Korney Chukovsky and Agniya Barto as the most popular poet writing for Russophone children. His poems about enormously tall "Uncle Styopa" ("Дядя Стёпа") enjoyed particular popularity.
As a 29-year-old in 1942, Mikhalkov's work drew the attention of the Soviet Union's leader Joseph Stalin, who commissioned him to write lyrics for a new national anthem. At the time, the country was deeply embroiled in World War II and Stalin wanted a Russian theme for the national anthem, to replace the Internationale.
Mikhalkov penned words to accompany a musical score by the composer Alexander Alexandrov (1883–1946) that became known as National Anthem of the Soviet Union. The new anthem was presented to Stalin in the summer of 1943 and was introduced as the country's new anthem on January 1, 1944.
Use of the Soviet anthem, with Mikhalkov's lyrics, continued until 1991, when it was retired by President Boris Yeltsin after the USSR disintegrated. However, when Vladimir Putin took over from Yeltsin in 2000, he began to clamor for a restoration of Alexandrov's music in place of Yeltsin's choice.