Joan Humphrey Lefkow (born January 9, 1944) is a United States district court judge for the Northern District of Illinois. She was nominated by President Bill Clinton on May 11, 2000, to a seat vacated by Judge Ann Claire Williams, and confirmed by the United States Senate on June 30, 2000. Lefkow received her commission on July 11, 2000.
Lefkow was born in Nemaha County, Kansas. She attended Wheaton College as an undergraduate, and obtained her Juris Doctor (J.D.) degree at Northwestern University law school in 1971. After graduation, she became a law clerk for Thomas E. Fairchild. From 1982 to 1997 she was a United States Magistrate Judge, and from 1997 to 2000 a U.S. Bankruptcy Judge for the Northern District of Illinois.
In May 2000, Judge Lefkow presided over the enforcement of a high-profile trademark infringement case against the World Church of the Creator, an organization run by white supremacist leader Matthew F. Hale. The TE-TA-MA Truth Foundation sued Hale's church for using the name Church of the Creator. Some argued against the validity of the suit because Hale's church had been using the name since 1973, but the Foundation had trademarked it in 1987, and no contest was filed against the trademark within a five-year period, making their ownership legally incontestable. In January 2002, Lefkow ruled in favor of Hale, but her decision was overturned on appeal. On July 25, Lefkow ruled against Hale, saying that his church infringed the Church of the Creator's trademark. (Hale's organization has since been renamed the Creativity Movement.)