Huaihai may refer to:
Huaihai Economic Zone, centered around Xuzhou, Jiangsu, China Baizhang Huaihai (720–814), Chinese Zen master Huaihai Campaign, 1948–1949 military action during the Chinese Civil War Huaihai Institute of Technology, institute in Lianyungang, Jiangsu, China Huaihai opera, traditional Chinese theatre Huaihai Road, street in Shanghai, China