Walesa's successful leadership in the August 1980 Gdansk shipyard strike in Poland earned workers the right to strike and to organize an independent union, Solidarity, of which Walesa served as chair. The union was suspended and Walesa interned in late 1981 when martial law was imposed in Poland. Released in November 1982, Walesa and other union leaders, although under surveillance, were able to keep the Solidarity movement alive. Walesa's work was recognized in 1983 with the Nobel Peace Prize.

Deteriorating economic conditions in Poland eventually forced its communist government to negotiate with Walesa and the Solidarity movement in the late 1980s, resulting in semi-free elections. Walesa was elected president of Poland in 1990, serving until 1995.

Today, Walesa is head of the Lech Walesa Institute. Established in 1995, the institute's activities include working to promote Poland and its people, as well as supporting democracy and a free-market economy in the country.