Mieczysław Zygmunt Jagielski was a Polish politician and economist. During the times of the People's Republic of Poland he was the last leading politician from the former eastern regions of pre-Second World War Poland.
Jagielski became a communist deputy to the legislative body of Poland, the Sejm, in 1957, and he would continue to serve in that capacity for seven consecutive terms until 1985. In 1959, he was posted to be a member of the Central Committee of the Polish United Workers' Party and appointed to be the Minister of Agriculture. After he left his position as Minister of Agriculture in 1970, Jagielski became a Deputy Prime Minister, and the next year, a member of the Politburo of the Polish United Workers' Party. In August 1980, Jagielski represented the government during talks with strikers in the city of Gdańsk. He negotiated the agreement which recognized Solidarity, a Polish trade union, as the first officially recognized independent trade union within the Eastern Bloc. Between August 1980 and August 1981, Jagielski continued to interact with representatives of Polish workers, though his health was declining during this period.