The Yangtze Delta or Yangtze River Delta (YRD), once known as the Shanghai Economic Zone, is a megalopolis generally comprising most parts of Shanghai, southern Jiangsu, northern Zhejiang, and southern Anhui. The area lies in the heart of the Jiangnan region (literally meaning "south of the Yangtze"), where the Yangtze drains into the East China Sea. Historically, the fertile delta fed much of China's population, allowing cities and commerce to flourish. Today, it is one of China's most important metropolitan areas and is home to China's financial center, as well being as a tourist destination and a hub for manufacturing ranging from textile to automaking. In 2024, the Yangtze Delta had a GDP of approximately US$4.7 trillion (about the same size as Germany).
The urban buildup in the area has given rise to what may be the largest concentration of adjacent metropolitan areas in the world. It covers 350,000 km (140,000 sq mi) and is home to over 240 million people, about a sixth of China's population. With a fourth of the country's GDP, the YRD is one of the fastest growing and richest regions in East Asia.