The South Pars/North Dome field is a natural-gas condensate field located in the Persian Gulf. It is by far the world's largest natural gas field, with ownership of the field shared between Iran and Qatar. 

This gas field covers an area of 9,700 square kilometres (3,700 sq mi), of which 3,700 square kilometres (1,400 sq mi) (South Pars) is in Iranian territorial waters and 6,000 square kilometres (2,300 sq mi) (North Dome) is in Qatari territorial waters.

In-place volumes are estimated to be around 1,800 trillion cubic feet (51 trillion cubic metres) gas in place and some 50 billion barrels (7.9 billion cubic metres) of natural gas condensate in place.

With in place volumes equivalent to 360 billion barrels (57 billion cubic metres) of oil (310 billion boe of gas and 50 billion boe of natural gas condensate) the field is the world's biggest conventional hydrocarbon accumulation.

The estimates for the Iranian section are 500 trillion cubic feet (14×1012 m3) of natural gas in place and around 360 trillion cubic feet (10×1012 m3) of recoverable gas which stands for 36% of Iran's total proven gas reserves and 5.6% of the world's proven gas reserves. 

The estimates for the Qatari section are 900 trillion cubic feet (25×1012 m3) of recoverable gas which stands for almost 99% of Qatar's total proven gas reserves and 14% of the world's proven gas reserves.

According to en.wikipedia