National Fuel Gas Company is an integrated energy company with $6.2 billion in assets distributed among the following five operating segments: Exploration and Production (Seneca Resources Corporation), Pipeline and Storage, Gathering, Utility, and Energy Marketing (National Fuel Resources, Inc. - NFR). National Fuel Gas was incorporated in 1902 and is based in Williamsville, New York.

The Utility segment sells natural gas or provides natural gas transportation services to more than 732,000 customers through a local distribution system located in western New York and northwestern Pennsylvania. The Pipeline and Storage segment provides interstate natural gas transportation and storage services for affiliated and non-affiliated companies through an integrated system of 2,972 miles of pipeline and 31 underground natural gas storage fields (including 4 storage fields co-owned with nonaffiliated companies). The Exploration and Production segment, headquartered in Houston, Texas, explores for, develops and produces natural gas and oil reserves in California, Kansas and the Appalachia Region. Seneca’s primary focus is now the Marcellus and Utica Shales in Pennsylvania, where the company controls 780,000 net prospective acres. The Energy Marketing segment markets natural gas to industrial, commercial, public authority and residential end users located in New York and Pennsylvania.

As one of the earliest gas utility companies in the United States, National Fuel Gas witnessed a number of technological firsts at its company or its subsidiaries. Engineers at the company discovered that depleted underground gas fields could be modified to act as storage reservoirs. Thus, the first such storage facility in the US was implemented at Zoar Field, about forty miles south of Buffalo. This turned out to be a great financial asset to NFG in the 1940s and 1950s, when skyrocketing demand for natural gas led to extensive pipelines in the eastern states being connected to new pipelines and fields in the southwestern states. NFG could thereby purchase huge quantities of cheaper summer gas from the southwest, pipe it to its New York storage fields, inject it into the ground, then retrieve it when demand and prices rose in the winter months.

The company was also the first in the industry to develop a gas-fired generator to produce electricity for cathodic protection to fight corrosion on pipelines.

In 1975, with the introduction of "Balanced Billing", the company claimed that it was "the only gas utility in the country" with a flexible plan for customers to pay bills in eleven equal monthly payments, with settlement of any overpayment or underpayment in the twelfth month. This is a modified system of installment credit.

Its headquarters was located at 10 Lafayette Square until 2002 when the company relocated to 6363 Main St in the Buffalo suburb, Williamsville.

National Fuel Gas Co. is traded on the New York Stock Exchange under the ticker symbol NFG. Its fiscal year ends September 30.

National Fuel's direct, wholly owned subsidiaries include Horizon Energy Development, Inc.; Horizon LFG, Inc.; Leidy Hub, Inc.; Data-Track Account Services, Inc.; Horizon Power, Inc.; Empire Pipeline, Inc. and Seneca Resources, Inc.