An independent regulatory commission hearing imposed the sanction, which has been backdated to May 23 when he voluntarily withdrew from the England Under-21 squad.
However, a statement released by the Football Association revealed that the three months of the ban have been suspended until July 1 2016.
They will be automatically invoked upon a proven breach of the FA's betting rules during that period.
"Townsend, who was also fined £18,000, was charged for breaches of FA Rule E8(b) for misconduct in relation to betting, which he admitted and requested a personal hearing," read the statement.
With Townsend's ban effectively reduced to one month, the 21-year-old will be available for the start of the 2013-14 Barclays Premier League season.
He spent a successful loan spell at QPR, arriving at Loftus Road in January, and while the club were relegated he received frequent praise from manager Harry Redknapp.
Once the FA had charged him with breaching their betting regulations, he pulled out of England's squad for the European Under-21 Championship in Israel and was replaced by Birmingham's Nathan Redmond. Townsend was not accused of betting on matches he had any involvement in, but the FA operates strict rules that forbid gambling on a wide spectrum of games.
A product of the Tottenham academy who had loan spells at various clubs, including Ipswich, Millwall, Leeds and Birmingham, he came to prominence at QPR last season with his energetic displays, emerging as one of the few highlights of a disastrous season.
With the future of Gareth Bale in some doubt - Real Madrid are leading the chase for the Wales winger - Townsend could be close to breaking into Spurs' first team.
Source: PA
Source: PA