Zygmunt Modzelewski (15 April 1900 – 18 June 1954) was a Polish communist politician, professor, economist, and diplomat.

In 1937 he moved to the Soviet Union and was arrested by NKVD in the same year in the Great Purge.

In May 1943 he was involved in the formation of the Polish 1st Tadeusz Kościuszko Infantry Division in the camp in Seltsy.

He held this position until June 28, 1945, when the Moscow Conference on the establishment of the Provisional Government of National Unity ended.

He was also a Polish delegate to the session of the Preparatory Commission of the United Nations.