[2] Viola is the owner of the Florida Panthers of the National Hockey League (NHL),[3] and the founder and chairman of Virtu Financial.

[4] He is also the owner of St. Elias Stables and co-owner, with fellow Brooklynite Anthony Bonomo, of the 2017 Kentucky Derby winner Always Dreaming.

[6] Viola was born in 1956 to an Italian-American family in the Williamsburg neighborhood of Brooklyn, New York City, the son of Virginia (Torre) and John A.

[10] Upon graduating from Brooklyn Technical High School, Viola attended the United States Military Academy[10] at West Point, New York.

After graduating from the Infantry Officer Basic Course and Ranger School, he served with the 101st Airborne Division at Fort Campbell[12] for several years.

[17] Leah McGrath Goodman's 2011 book, The Asylum: The Renegades Who Hijacked the World's Oil Market, describes Viola and his temperament.

Goodman wrote that Viola "had a nasty temper, but [predecessor chairman Lou] Guttman says he didn't lose control of his emotions easily" and that "beneath the spit and polish he was still a tough guy from Brooklyn."

[21] Viola withdrew himself from consideration for the position on February 3, 2017, citing his inability to comply with Pentagon regulations regarding personal businesses.

[22] After the September 11 attacks, Viola helped found the Combating Terrorism Center at West Point, and was the principal funder at its creation.