ONO was a Spanish broadband communication and entertainment company, delivering integrated telephone, television and Internet services to its residential customers. In this segment, it has 3.7 million services contracted and over six million users.

ONO was incorporated in 1998. Before commencing its operations, ONO's then-parent company Cableuropa (founded in 1992) took part in a series of competitive tenders which were called after the coming into force of Spain's General Telecommunications by Cable Act 42/95. From 1996 to 1998, ONO was awarded the licenses to provide cable television and telecommunications services in the regions of Valencia, Castellon, Alicante, Murcia, Cádiz, Huelva, Cantabria, Majorca and Albacete.

As the company rolled out its own latest-generation network across its regions, users started to enjoy its TV, telephone and Internet services. By the end of 2002, ONO was already present in approximately one in every three homes prepared to receive its services. A year later, it was awarded the license to operate in Castile-La Mancha and, in 2004, it acquired the telecommunications operator Retecal, covering Castile and León, Spain’s second largest region by geographical area.

In November 2005, ONO closed the acquisition of 100% of the telecoms company Auna Tlc, thereby consolidating its presence as Spain's leading broadband communications and entertainment company and extending its services to the communities of Aragon, Andalusia (excluding Cadiz and Huelva, which already belonged to ONO), the Canary Islands, Catalonia, La Rioja, Madrid and Navarra.

On 17 March 2014, ONO announced it would be acquired by Vodafone Spain for €7.2 billion (US$10 billion), subject to regulatory approval. Vodafone retired the ONO branding on 8 April 2019.