Mariani (IPA: ˌmɑːrɪˈænɪ) is a neighbourhood town of Jorhat. It is about 17.5 km from Jorhat Town railway station. Mariani is in the border of Nagaland. Mariani is famous for the Gibbon Wildlife Sanctuary which is located on the roadside on the way to Nakachari from Mariani at a distance of 5 km. Pincode of Mariani is 785634.

This small town is surrounded by some of the largest tea gardens in India. Mariani has a cosmopolitan culture with many communities speaking different languages and living in harmony for decades. The town was once well known for having one of the largest plywood factories in India which was later closed down as felling trees was banned by law. In Assamese, moriya is a fisherman and his wife is called moriyani. The name mariani was derived from moriyani.

Mariani is located at 26°40′N 94°20′E / 26.67°N 94.33°E / 26.67; 94.33. It has an average elevation of 155 metres (509 ft).

As of 2001 India census, Mariani had a population of 23,065. Males constitute 54% of the population and females 46%. In Mariani, 12% of the population is under 6 years of age.

Bengali is the most spoken language at 12,401 speakers, followed by Assamese at 4,344 and Hindi at 3,238.

Dhodar Ali connects Mariani by road. Mariani is well connected with Jorhat by road. Buses and mini vans (Tata Magic) are available frequently. The nearest airport of Mariani is Jorhat Airport. The town has very good railway connectivity with rest of the country. It is served by Mariani junction, one of the major railhead of Tinsukia railway division. It falls in the Lumding–Dibrugarh section.

• Mariani College

• Adarsh Hindi Vidyalaya
• Bongshi Gopal High School
• Edith Douglas HS School
• Railway High School, Mariani
• Little Star School
• Mahadev Agarwalla Higher Secondary School
• Mariani Girls' School
• Mariani High School
• Mariani Jatiya Vidyapith
• Parijat Jatiya Vidyalaya
• St. Antony's High School
• Asset Academy
• Mann International School
• Bheleuguri Adarsha High School
• Jungle Block High School
• 218 No Sonowal LP School

Mariani is part of Jorhat (Lok Sabha constituency).BJP's Rupjyoti Kurmi is the incumbent MLA of Mariani (Vidhan Sabha constituency).
In 2022 Assam municipal elections, The Independent Candidates with Mariani Unnayan Mancha won seven wards out of ten wards, reducing BJP to two in Mariani Municipal Corporation.

• Anamika Choudhari, winner of Sa Re Ga Ma Pa L'il Champs International
• Rupjyoti Kurmi, Indian politician