Cronan earned his Bachelor of Arts, magna cum laude, from Georgetown University in 1998, where he was inducted into Phi Beta Kappa, and his Juris Doctor from Yale Law School in 2001.

[3] After graduating from law school, Cronan served as a law clerk to Judge Barrington D. Parker Jr. on both the United States District Court for the Southern District of New York and the United States Court of Appeals for the Second Circuit from 2001 to 2002.

Immediately before becoming a judge, Cronan was the Principal Deputy Assistant Attorney General for the Criminal Division from 2017 to 2020.

[3] Cronan was previously an adjunct professor at New York University School of Law from 2015 to 2017, where he co-taught a seminar on federal criminal prosecutions.

President Trump nominated Cronan to the seat vacated by Judge William H. Pauley III, who assumed senior status on March 1, 2018.