No. There's a race builder where you can make a race large for a certain amount of race points. It's on the PRD under Advanced Race Guide > Race Builder. As someone who rode a horse his entire last campaign though, let me tell you, being large is a liability in most instances.
The reason why most playable races are either medium or small is becasue the game gets into weird places when you are constantly large, particularly at low levels.
This is because large humanoids have a reach of 10 feet, and they take up 10 feet of space. That means they cover a 30' circle of threatened area. That is better than a medium reach build, and it doesn't have problems with adjacent squares. And a large creature could do all this with 3d6 greatswords.
Invalidating a large swath of weapons is kind of a problem. There is a reason why one of the design assumptions for martial monsters is "Higher CR=Bigger".
The Trox is one such race, but it's totally unbalanced for most groups of PCs as a CR +2 race.
The third party psionic race half giant has powerful build which gives some of the benefits of being large while still being medium. Like you can use large weapons and count as large for stuff like grappling, but medium for armor pricing, fitting into areas etc.