The fading impact of austerity and implementation of reforms in some of the euro zone's most vulnerable countries has helped the bloc turn a corner, the Commission said.
But it warned that a failure to continue with reforms, combined with "sustained very low inflation" in the euro area, would present risks to the rebalancing of the region's economy.
(Read more: Euro to strengthen even on ECB easing?)
"The worst of the crisis is behind us but this is not an invitation to be complacent," Ollie Rehn, the European commissioner for economic and monetary affairs, said at a press conference on Tuesday.
Greece, Spain and Italy - which were among the countries worst hit by the economic crisis and have suffered economic contractions over the past two years - look to be turning around, according to the Commission's winter forecast.
Greece is forecast to grow 0.6 percent in 2014 and 2.9 percent in 2015, while Spain is set to see 1 percent growth this year and 1.7 percent growth the following year.
Italy, amid optimism about new Prime Minister Matteo Renzi's thirst for reform, is expected to grow by 0.6 percent in 2014 and 1.2 percent next year. While the U.K. will see strong growth of 2.5 percent this year and 2.4 percent in 2015, according to the Commission.
(Read more: Foreign trade driving German growth)
In 2014, only Cyprus and Slovenia are expected to continue to register negative annual growth rates, but by 2015 all economies are expected to expand again.