1981: Doireann Ní Bhriain

Doireann Ní Bhriain (pronounced [ˈdˠərʲiːn nʲiː ˈvrʲiːənʲ], is an Irish independent radio producer.^[1][2] She began her career as a radio and television journalist,^[3] and started out reading children's stories on television. From those beginnings, she went on to work for RTÉ for over 20 years before moving on in 1993.^[4] She is best known for her work and affiliation with RTÉ Radio 1.^[2]
She was a long-running reporter on the radio current affairs programme Women Today,^[5][6][7] for which she is well-known. She was the mistress of ceremonies at the Eurovision Song Contest 1981, held in Dublin.^[8] In 1993, she won a Jacob's Award for her work on RTÉ Radio.^[9]

Outside of Ireland, Doireann is best known for being the solo presenter of the 1981 Eurovision Song Contest.
The dress she wore for the occasion was designed by Richard Lewis, while the gold jewellery was designed by Mary Grey.^[11]
In a 2004 interview with the Sunday Times (Irish edition), she said of the experience, "I did it for a laugh...it was offered me because I was quite well known, and because I spoke French and Irish with some ease...I always tell people that there was no autocue in those days: I had to learn it all off."^[4]
Ní Bhriain provided the RTÉ Radio commentary for the 1991 Contest.

From: http://en.wikipedia.org/wiki/Doireann_N%C3%AD_Bhriain

As the host in 1981.