The newsreader will finish at the end of April, after 37 years with the broadcaster.
Most recently he has presented the News at One on RTE Radio One, having spent time on the Six One and the Nine O'Clock News.
He has presented all of RTÉ's flagship news programmes across television and radio during this time and anchored RTÉ's television coverage of elections, and special state events.
Speaking about his departure for the first time, Bryan Dobson said:
"After 37 fantastic years with RTÉ the time has come to move on. I will miss working with some wonderfully talented and hardworking colleagues. RTÉ journalism depends on teamwork and I have worked with some of the very best. I am grateful too to the listeners and viewers who have give me their time and attention over the years. I hope to have repaid that trust with reporting that was relevant, fair and accurate"
