Gleeson worked as a law clerk for Boyce Martin on the United States Court of Appeals for the Sixth Circuit from 1980 to 1981.

[3] Gleeson's ruling against the FBI in a landmark racial profiling case was reversed by the Supreme Court of the United States in Ashcroft v. Iqbal (2009).

[5] In his last days on the bench Judge Gleeson, instead of issuing a writ of audita querela,[6] created a new "federal certificate of rehabilitation" to help convicts find jobs.

[7][8] On January 4, 2016, it was announced that Gleeson planned to resign from the bench and return to private practice on March 9, 2016.

"[12][13] On May 11, 2022, President Joe Biden announced his intent to nominate Gleeson to serve as a member of the United States Sentencing Commission, to replace the retiring Rachel Barkow.