Igor Gräzin (birth name: Russian: Игорь Николаевич Грязин, romanized: Igor Nikolayevich Gryazin (born 27 June 1952 in Tartu) is an Estonian academic and politician currently serving as a member of the Tallinn City Council. He is a former member of Riigikogu and former Member of the European Parliament. Currently sitting as an independent city councillor, he was formerly affiliated with the Reform Party until 2019 and the Centre Party until 2024.

Grazin began his career as a professor of law at Tartu State University. After the dissolution of the Soviet Union he taught at the University of Notre Dame in the United States until 2000, after that at the University Nord in Tallinn (as the Dean of the Law School and the Vice President). He has also served as a research fellow at the Woodrow Wilson Center in Washington D.C.

Grazin was elected to the Supreme Soviet of the Soviet Union in 1989 as a candidate of the Popular Front of Estonia and served until its dissolution in 1991.

Gräzin proposed restoring the Estonian maritime border to where it was before 1993, allowing Estonian access to the Nord Stream 1 gas pipeline.

He opposed the decision to sentence Saddam Hussein to death without a jury.

An Eurosceptic, he was a dissenting voice in the strongly pro-EU Reform Party. He was the only Riigikogu member to vote against ratifying the Treaty establishing a Constitution for Europe.

He supports abolishing the Estonian presidency and implementing a bicameral legislature with 80 members in the lower house and 40 in the upper house.

He is functionally trilingual in Estonian, English, and Russian.