RTÉ's teletext service Aertel will be shut down from next Thursday.
The service has provided news, TV schedules, sport scores, weather and more for almost 40 years.
It was first launched back in 1987, but has been running digitally since 2019.
The broadcaster said the closure is part of a strategy it published back in 2019 for an "ongoing and necessary evolution into a public service media organisation".
It said the need to prioritise the delivery of digital services has seen resources previously given to Aertel diverted online.
Changes to legislation also mean that RTÉ is no longer legally required to provide a teletext service.
The broadcaster said the decision to close was based on three main factors.
The availability of Aertel content across other services, increased demand for content online and a lack of support technology available for Aertel.
"Many technical components in the Aertel systems are no longer supported by the manufacturer, with further elements losing support later this year," RTÉ said.
"The technology required to deliver the Aertel service has limited availability and is not supported on many newer TVs or set top boxes," it added.
In the UK, the BBC discontinued its teletext Ceefax service back in 2012.