October 4, 2012
ABC Family announced today that Pretty Little Liars has been renewed for a fourth season. The teen drama will return with another 24 new episodes starting in mid 2013.
The series has been going strong since debuting in the summer of 2010, and is currently ranked as the network's #1 series of all time. Currently in a mid-season break, Pretty Little Liars will once again air a special Halloween-themed episode on Tuesday, October 23, 2012. The remainder of its regular third season episodes will resume airing in January 2013.
UPDATE: Season 4 of PLL premieres on Tuesday, June 11, 2013.
(Source: TV by the Numbers)