Python reticulatus, also known as the (Asiatic) reticulated python, is a species of python found in Southeast Asia. Adults can grow to 6.95 metres (22.8 ft) in length but normally grow to an average of 3-6 meters (10–20 feet). They are the world's longest snakes and longest reptile, but are not the most heavily built. Like all pythons, they are nonvenomous constrictors and normally not considered dangerous to humans. Although large specimens are powerful enough to kill an adult human, attacks are only occasionally reported.

An excellent swimmer, Python reticulatus has been reported far out at sea and has colonized many small islands within its range. The specific name, reticulatus, is Latin meaning "net-like", or reticulated, and is a reference to the complex color pattern.

In general, reticulated pythons with lengths of more than 6 metres (20 ft) are rare. One of the largest scientifically measured specimens, which was from Balikpapan, East Kalimantan, Indonesia, was measured under anesthesia at 6.95 metres (22.8 ft) and weighed 59 kilograms (130 lb) after not having eaten for 3 months. Widely published data of specimens that were reported to be several feet longer have not been confirmed.