Podolski retires as Germany's third highest capped player with 129 appearances, behind only Lothar Matthaeus and Miroslav Klose, having scored 48 goals.
"Everything has its time - and my time with the DFB (the German Football Federation) is over," Podolski said in a statement on his Instagram account.
The 31-year-old said he has informed coach Joachim Loew of his decision.
"I am dedicating myself more to other things, mainly my family," he explained. "The national team has always been in my heart, and they always will be, but I felt after the Euros and the vacation that my focus has shifted."
Podolski, who currently plays for Galatarasaray, was an unused substitute in the 2014 World Cup final when Germany edged Argentina in extra-time to claim a fourth title.
He made one brief substitute appearance at his seventh major tournament as Germany reached the semi-finals of Euro 2016 where they were defeated by France.
He made his Germany debut as a teenager in 2004 despite interest from Poland, the land of his birth, and was voted best young player of the 2006 World Cup on home soil.
"From a two-year-old Polish boy who came to Germany with a ball under his arm to a world champion," he added. "That's more than I have ever dreamed about.
"12 years, 129 matches. It was amazing! It was great! It was an honour to be part of Germany."
(Reporting by Ed Dove; editing by Sudipto Ganguly)
