Summer Sonic (サマーソニック, Samā Sonikku) is an annual music festival held on one weekend in August simultaneously in both Chiba and Osaka, Japan.

International versions of the festival have occasionally been held outside Japan, including Shanghai in 2017 and Bangkok in 2024.

The Chiba event takes place every August at the massive Makuhari Messe convention center, which overlooks Tokyo Bay, with the main stage located in nearby Zozo Marine Stadium.

In 2011, the festival established Sonicmania, whose focus is on electronic dance music (EDM).

Possibly because of the logistics of moving people around during a pandemic, the 2021 lineup was mainly electronic.