The third member of the Leon family combines the design and handling qualities of its siblings with a greater amount of practicality.
The estate car measures 4,535mm long - 264 mm longer than the five-door Leon.
It has a load capacity of 587 litres, rising to 1,470 litres with the rear seat backrests folded.
ST's twin-level boot floor makes loading bulky items easier; the rear seats can be folded flat using handles on the sidewalls of the boot.
"Nobody has to choose between sporty and practical anymore - the new Leon ST offers both," said Jürgen Stackmann, President and CEO of SEAT SA.
"With its sporty look, its surprisingly high utility and its state-of-the-art technology, the Leon ST defines a new standard in the compact estate car class - at a very fair price.
"Like the already highly successful Leon and Leon SC, the new ST is the perfect representative of SEAT's brand values," he added.