The Meghna River (Bengali: মেঘনা নদী) is one of the most important rivers in Bangladesh, one of the three that forms the Ganges Delta, the largest on earth fanning out to the Bay of Bengal. Being a part of the Surma-Meghna River System, Meghna is formed inside Bangladesh by the joining of different rivers originating from the hilly regions of eastern India. The river meets Padma River in Chandpur District. The river ultimately flows into the Bay of Bengal in Bhola District.

Major tributaries of the Meghna include the Dhaleshwari River, Gumti River, and Feni River. The Meghna empties into the Bay of Bengal via four principal mouths, named Tetulia (Ilsha), Shahbazpur, Hatia, and Bamni.

The Meghna is the widest river among those that flow completely inside the boundaries of Bangladesh. At one point near Bhola, Meghna is 12 km wide. In its lower reaches this river follows almost a straight line in its path. Despite its very calm and quiet look, this river is the cause of many deaths every year. Several ferry and launch sinkings in the past have killed hundreds, like the MV Salahuddin-2 and theMV Nasrin-1. Near Chandpur it is very dangerous.

The Meghna is a distributary of the Brahmaputra. The Meghna is formed inside Bangladesh by the joining of the Surma and Kushiyararivers originating from the hilly regions of eastern India. Down to Chandpur, Meghna is hydrographically referred to as the Upper Meghna. After the Padma joins, it is referred to as the Lower Meghna.

Near Muladhuli in Barisal district, the Safipur River is an offshoot of the Surma that creates one of the main rivers in South Bengal. 1.5 km wide, this river is one of the widest in the country as well.^{[citation needed]}

At Ghatalpur of Brahmanbaria District, the river Titas emerges from Meghna and after circling two large bends by 240 km, falls into the Meghna again near Nabinagar Upazila. Titas forms as a single stream but braids into two distinct streams which remain separate before re-joining the Meghna.

Meghna is reinforced by the Dhaleshwari before Chandpur as well. The name for the largest distributary of the Ganges in Bangladesh is the Padma River. When the Padma joins with the Jamuna River, the largest distributary of the Brahmaputra, and they join with the Meghna in Chandpur District, the result in Bangladesh is called the Lower Meghna. When the brown and hazy water of the Padma mix with the clear water of the Upper Meghna, the two streams do not mix but flow in parallel down to the sea - making half of the river clear and the other half brown. This peculiarity of the river is always a great attraction for people.In Daudkandi, Comilla, Meghna is joined by the great river Gomoti, created by the combination of many streams. This river reinforces Meghna a lot and increases the waterflow considerably. The pair of bridges over Meghna and Gomoty are two of the country's largest bridges. The Dakatua River is also part of the river system in Comilla district.

After Chandpur, when the river has the combined flow of the Padma and Jamuna it moves down to the Bay of Bengal in an almost straight line. In her course from Chandpur to Bay of Bengal, the Meghna braids into a number of little rivers including the Pagli, Katalia, Dhonagoda, Matlab and Udhamodi. All of these rivers flow out from the Meghna and rejoin again at points downstream.

Near Bhola, just before flowing into the Bay of Bengal, the river divides into two main streams in the Ganges delta and separates an island from both sides of the mainland. The western stream is called Ilsha and the eastern one is called Bamni.