Exclusive: Oscar winner J.K. Simmons has been tapped as the lead of The Westies, MGM+’s upcoming period crime drama series from co-creator, executive producer and showrunner Chris Brancato.

Co-created by Brancato and Michael Panes, The Westies is set in the early 1980s when the construction of the Jacob Javitz Convention Center on the Westies’ home turf in Hell’s Kitchen promises a financial windfall for the Irish-American organized crime gang. Despite being outnumbered 50-to-1 by the Five Families of the Italian mafia, the Westies’ legendary brutality and cunning have given them the leverage necessary to share the spoils through a fragile détente. But internal conflict between the brash younger generation and the old-school leadership threatens to set a match to this powder keg, which will sweep the Westies into the FBI’s ever-deepening investigation into the Italian mafia.

Simmons will play Eamon Sweeney, the charismatic but ruthless leader of...