The 23-year old Japan international has joined the Bavarian club from J.League outfit Kashima Antlers on a three-and-a-half-year deal.
1860's sporting director Florian Hinterberger was thrilled to complete the transfer of a player who is looking to force his way into the Blue Samurai squad for this summer's World Cup in Brazil.
We're delighted to have been able to sign a player of his calibre," said Hinterberger.
"Yuya wants to play well so that he can go to the World Cup in Brazil with Japan. For us, that means we can boast a strong attack in Bundesliga 2."
Osako, who had been with Kashima since 2009, added: "The Bundesliga 2 is incredibly strong and 1860 are a side with a great tradition who are known even in Japan.
"I would like to support the club in achieving their objectives with my good performances and goals. This is the best opportunity for me to secure a place in the national team too."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball