The Gulf of Khambhat is a trumpet shaped bay that is part of the Arabian Sea coast of India that borders the state of Gujarat. The Gulf divides the Kathiawar Peninsula from the south-eastern part of Gujarat. The Gulf of Khambhat is also known as the Gulf of Cambay. Several major rivers drain from Gujarat into the Gulf, including the Narmada, the Tapti, the Mahi and the Sabarmati.

The Gulf of Khambhat is about 200 kilometres in length and around 20 kilometres wide in the north and up to 70 kilometres wide in the south. The shape and orientation of the Gulf in relation to the south-west monsoon winds is the reason for its high tidal range of 12 metres and the high velocity of the entering tides. The shoals and sandbanks are hazardous to navigate, and all the ports in the Gulf have suffered from silting caused by the tides and flood torrents of the rivers. The Gulf region is very tectonically active, and several faultlines are found here, with earthquakes occurring periodically. The Gulf itself was formed by a major rift that caused a down sliding of the Khambhat region.

One of the oldest Indian ports Bharuch and the port of Surat are found on the eastern side of the Gulf which were more active during the period of early European commercial contact with India. The discovery and exploration of oil, in particular near Bharuch, has resulted in a commercial revival of the region.