Telecommunications in the United Kingdom have evolved from the early days of the telegraph to modern fibre broadband and high-speed 5G networks.

Altice USA, Inc., commonly known as Altice, is an American telecommunications provider with headquarters in New York City, owned by the Franco-Israeli businessman Patrick Drahi. The company delivers pay television, Internet access, telephone services, and original television content to approximately 4.9 million residential and business customers in 21 U.S. states. Altice USA is based at One Court Square in Long Island City, Queens, New York City. The company's operational center is located at Cablevision's former headquarters in Bethpage, Nassau County, New York, on Long Island. With its combined brands, Altice USA is the fourth-largest cable provider in the U.S., serving customers residing in the New York metropolitan area as well as in several Midwestern and Southern U.S. states.
Oi, formerly known as Telemar, is the largest fixed telephone operator and the fourth mobile telephone operator in Brazil, being the third largest telecommunication company in Latin America. It is headquartered in Rio de Janeiro.

Mediacom Communications Corporation is the United States' fifth-largest cable television provider based on the number of video subscribers, and among the leading cable operators focused on serving smaller cities and towns. The company has a significant concentration of customers in the Midwest and Southeast, and is the largest broadband provider in Iowa. Founded in 1995 by Rocco B. Commisso, the current owner of the New York Cosmos and ACF Fiorentina. Mediacom is headquartered in New York and incorporated in Delaware, United States. Formerly a publicly traded firm, it went private in a $600 million transaction in March 2011 and is owned solely by Commisso as of 2011.

SFR is a French telecommunications company. It is both the second-oldest mobile network operator and the second largest telecommunications company in France, after Orange.

Altice Portugal S.A. is the largest telecommunications service provider in Portugal. Since 2 June 2015 the company has been a wholly owned subsidiary of Altice, a multinational cable and telecommunications company with a presence in France, Israel, Belgium, Luxembourg, Portugal, French West Indies/Indian Ocean Area, the Dominican Republic, and Switzerland. It currently owns the MEO, Moche and SAPO brands.

nTelos, Inc. was a wireless telecommunications company and PCS provider based in Waynesboro, Virginia. As of 2013, nTelos' service area covered 5.3 million people making it the 9th largest provider of mobile broadband in the United States.

Frontier Communications Parent, Inc. is an American telecommunications company. Known as Citizens Utilities Company until 2000, Citizens Communications Company until 2008, and Frontier Communications Corporation until 2020, as a communications provider with a fiber-optic network and cloud-based services, Frontier offers broadband internet, digital television, and computer technical support to residential and business customers in 25 states. In some areas it also offers home phone services.

Windstream Holdings, Inc., also doing business as Windstream Communications is a provider of voice and data network communications, and managed services, to businesses in the United States. The company also offers residential broadband, phone and digital streaming TV services to consumers within its coverage area. It is the ninth largest residential telephone provider in the country with service covering more than 8.1 million people in 21 states.
Numericable was a major French cable operator and telecommunications services company. Numericable was originally created in 2007 from the merger between former competitors Noos and NC Numericable networks. Numericable Group SA was founded in August 2013 to act as the parent company of Numericable group companies and to offer its shares on the stock exchange. The company provides cable broadband services in France, Luxembourg and Portugal, offering digital and analog television, Internet, and phone services to homes. From 2008, Numericable also offered mobile telephone services to its customers.

The Internet in the United States grew out of the ARPANET, a network sponsored by the Advanced Research Projects Agency of the U.S. Department of Defense during the 1960s. The Internet in the United States of America in turn provided the foundation for the worldwide Internet of today.

GTT Communications, Inc. (GTT), formerly Global Telecom and Technology, is a Network as a Service (NaaS) and Security as a Service (SECaaS) provider headquartered in Arlington, Virginia. GTT operates a Tier 1 IP network and provides Internet; wide area networking, SD-WAN; network security, voice and video transport services.
Global Capacity is a Waltham, Massachusetts-based provider of telecommunications Connectivity-as-a-Service including Carrier Ethernet, used by companies for Internet access and WAN connectivity. Network services are offered using the company's One Marketplace hub, which aggregates the access and pricing information for broadband telecommunications services, including MPLS VPN, Ethernet over copper and Digital Subscriber Line (DSL). The company buys and combines multiple high-speed network connections and then resells multiple lower-speed connections to customers. The company also manages and updates LATTIS, a proprietary database of telecom pricing information.