3rd Winx Movie: The Mystery of the Abyss

The third film will debut in Italy this fall in September. This film will fall between the lines of season 5 and season 6 in the series.
This time the Winx Club are back in the Infinite Ocean's depths. The Trix are teaming together with Politea to free from his prison cell Tritannus, swapping his life with Bloom's lover Prince Sky!
Their evil plan is to conquer the Magical Dimension getting ever so close to their success that this time they shall succeed once and for all! But to the save the Prince, Bloom must count on her friend's like never before, her and the Winx and the small Selkie will go together to defeat Tritannus, the Trix and Politea for good!

Season 7 News

It has been officially confirmed that a seventh season of Winx Club will be produced, and will air in 2015. An official teaser summary of the season states that: "Each fairy will have an animal that has a special talent, necessary for the balance of the Magic Universe. The Winx will discover this, while facing two new dreadful villains and getting new amazing transformations along their journey." However it is still unknown whether an English dubbed will be produced and further details of the plot are still not known.

Source: wikipedia.com