Chong Nonsi (Thai: ช่องนนทรี, pronounced [t͡ɕʰɔ̂ŋ nōn.sīː]) is one of the two khwaengs (sub-districts) of Yan Nawa District, Bangkok rim Chao Phraya River.

The name "Chong Nonsi" is derived from a folklore titled "Legend of Lord Uthong" (ตำนานท้าวอู่ทอง).

During his journey, he took a rest at a place near a river, they pretended that they were not royal family and he asked his wife to take off her tiara for their own safety.

Lord Uthong commanded his soldiers to tie a rope and made a raft to cross the Chao Phraya River.

The Lord and his wife settled down at a village for long time so that area was named "Chong Nang Ni" (ช่องนางหนี, "a channel that lady escaped").