The forward's part in an attack outside a Birmingham nightclub in the early hours of February 29 saw the former Walsall player kick a person in the head.
A man suffered a broken jaw and another received 20 stitches to the mouth as a results of the fracas and Deeney was sentenced to 10 months imprisonment on June 25.
The Hornets attacker wrote on Twitter: "Just to confirm to everybody I have been released from jail. Thanks for all your good and bad messages, will reply to as many as I can."
|33/1||Watford are 33/1 with Bet365 to win the Championship|
A statement, released on August 31, read: "Given the remorse demonstrated by Deeney, both in court and through his public apology, Watford is hopeful of reaching a resolution to support the player through his rehabilitation while he continues his playing career with the Hornets."
Solihull-born Deeney joined the Hertfordshire outfit from Walsall in 2010 and has made 79 first-team appearances for the club, scoring 13 times in total.