Davis is born on April 26, 1948 in Bangor, County Down, Northern Ireland to a Protestant father and a Roman Catholic mother. He attends St. MacNissi’s College, a Catholic boarding school in County Antrim and describes his early childhood life as ecumenical. During his childhood he acquires a love of boats which later provide the inspiration for the TV series Out of the Blue.
Davis starts as a news reporter with the American network ABC and BBC Northern Ireland before spending 11 years in the newsroom at RTÉ. In the early 1980s he becomes a newsreader for The Six-o-clock News and begins to become well-known due to his sometimes off-the-cuff comments on news stories.
Davis impersonates Big Tom on the RTÉ satirical programme Hall’s Pictorial Weekly and, as a result, is offered a part in a show-band in Cork. After a ballroom tour, he joins RTÉ proper in 1975, initially to work as a television news reporter, eventually becoming newsreader on the nine o’clock news. In the mid-1980s, he hosts his own talk show, Davis at Large. It is on this show, which is screened live, that he is attacked and hurled across the studio by a guest female body builder. In addition to this he has an interactive summer current affairs show, simply called Davis. In 1986, he begins co-hosting (with Thelma Mansfield) RTÉ 1’s afternoon programme Live at 3, a role he fills for eleven years.
Davis presents the Rose of Tralee twice in 1995 and 1996, the first of these when Gay Byrne is taken ill at short notice. He memorably thanks the providers of the air conditioning while wiping sweat from his brow. Live at 3 comes to an end in 1997. Davis returns to the screen in the late 1990s with a marine programme devoted to boats and the waters around Ireland called Out of the Blue, which runs for four series, the last of which is broadcast in 2001.
In 2000, Davis presents a radio quiz show called A Question of Food. During the summer season he takes over RTÉ Radio 1‘s mid-morning slot usually occupied by Today with Pat Kenny, and he also hosts the radio phone-in show, Liveline, when regular presenter Joe Duffy is on holiday. Later, he presents Sunday Magazine with Davis on 4 on 4fm.
In 2005, Davis hosts a show called Time on Their Hands, a travel series for older people. One of his last television appearances is on the second season of Celebrity Bainisteoir in 2009, in which he and seven other Irish celebrities manage an intermediate Gaelic football club team from their home county in an official GAA tournament. Davis’s team wins the tournament.