The 35-year-old former AC Milan and Chelsea forward ended his international career when Ukraine failed to progress from the group stage at June's Euro 2012, which they co-hosted with Poland.
His final - and first - club Dynamo Kiev released the news of his complete retirement from football in a statement.
"Perhaps, I will shock everyone: my future has nothing to do with football," Shevchenko said. "It is related to politics."
Shevchenko did not say if he planned to join one of Ukraine's existing political parties or create his own ahead of October's parliamentary election. He promised to announce the details on Saturday.
Another famous Ukrainian athlete, heavyweight boxing champion Vitaly Klitschko, already runs a political party called Udar (Strike).
Shevchenko started his career in Dynamo and then moved to Milan, becoming one of the most famous Ukrainian players. His following stint with Chelsea was less successful and since 2009 Shevchenko has been playing for Dynamo again.