[3][4] Riley graduated from Union-Endicott High School in 1999 and earned a bachelor's degree in government and economics from the College of William & Mary in 2003.

[8] He began attending Harvard Law School in 2004 and worked as a Heyman Fellow on the U.S. Senate Committee on Health, Education, Labor and Pensions.

[3] He graduated with a Juris Doctor in 2007 and was presented the Dean's Award for Community Leadership by then-Dean of Harvard Law School and current U.S. Supreme Court Justice Elena Kagan.

[5] In November 2021, Riley declared his candidacy for Congress in New York's 22nd congressional district, challenging incumbent Republican U.S. Representative Claudia Tenney.

[10] Due to redistricting, redrawing of the map by a court-appointed special master, and U.S. Representative Antonio Delgado resigning to become the Lieutenant Governor of New York, Riley ended up running in the new 19th congressional district.