The UEFA Euro 2012 will be played in Poland and Ukraine.

The 2012 UEFA European Football Championship, commonly referred to as Euro 2012, will be the 14th European Championship for national football teams sanctioned by UEFA. Poland and Ukraine will be the host nations of the final tournament, scheduled for mid-2012, following the selection of their joint bid by UEFA's Executive Committee, on 18 April 2007, in Cardiff, Wales. This bid defeated the other shortlisted bids from Italy and Croatia/Hungary, becoming the third successful joint-bid for the European Championship, after those of Belgium/Netherlands, for Euro 2000, and Austria/Switzerland for Euro 2008. This will be the last European Championship finals in which only 16 nations will participate, with Euro 2016 being the first European Championship finals with 24 competing nations.
http://en.wikipedia.org/wiki/UEFA_Euro_2012