Seoige was born in An Spidéal, County Galway, the youngest of four children, to parents Mairtín and Philomena. She attended Scoil Mhuire at primary level and Coláiste Chroí Mhuire at secondary level. After completing her Leaving Certificate, she was hired by TnaG to present a film show called Hollywood Anocht. Síle was introduced to the public after Gráinne, her sister, departed for TV3. There she interviewed Hollywood talent like Bruce Willis and Meryl Streep. When Hollywood Anocht ended Síle became TG4's weather girl and continuity presenter, and after two years she moved on to host a children's programme called Cúla4. After two years of Cúla4 Síle took a year out and spent that time travelling. She returned to Ireland to try radio presenting. She worked for Beat 101–102, a station based in the south-east before moving to national station Today FM. In the summer of 2004 Síle landed the job of covering Ireland's summer festivals for RTÉ's Nationwide.
Bilingual hosting
Following this, Síle presented RTÉ's Up for the Match and became a regular host on the bilingual programme Seachtain. This news and features format was very different for Síle, but she revelled in the opportunity to get out amongst the public and it gave her a firm footing in production, scripting and media law. Síle was also approached to be the face for Seachtain na Gaeilge, a week where everything Irish is celebrated. She produced a four-part series for RTÉ called Coiscéim and appeared with The Devilins on a compilation CD SnaG-05 featuring bands from Ireland singing in Irish language. In the summer of 2005, she took part in the first hugely successful You're a Star series, in which she raised over forty thousand euro for Galway-based charity, Cope. The following month she co-presented season four of the hit entertainment series. She co-presented live coverage of the St. Patrick's Day Parade for three years. She then presented a bilingual English-Irish current affairs programme on RTÉ One called Pobal. She has appeared as a guest presenter on travel programme No Frontiers and co-presented season one of RTÉ's entertainment series Class Act with Aidan Power. In 2007, she guest presented RTÉ's daytime programme The Afternoon Show with Bláthnaid Ní Chofaigh. She presented series five of TG4's flagship show Paisean Faisean with co-presenter Bláthnaid Ní Dhonnchadha. In October 2008, Síle joined her older sister Gráinne as co-presenter of Seoige on RTÉ One. After only one season together, RTÉ subsequently dropped the show leaving both sisters "very shocked". In September 2009, she started as a co-presenter on RTÉ's The Afternoon Show. She has since disappeared off Irish screens and can be heard on Newstalk radio, which signed her up in an attempt to increase its appeal to listeners in the West of Ireland. She made headlines in January 2012 as Ryan Tubridy interviewed personalities Lorraine Keane, Andrea Roche and Michael O'Leary on The Late Late Show when she tweeted: "Just wondering... are the days of the likes of Peter Ustinov, Spike Milligan and Germaine Greer gone forever?"
Personal life
Síle married Glen Mulcahy in a lavish ceremony in 2005. In January 2009, it was announced that the couple had separated and the marriage was over. In February 2012, she spoke about her battle with thyroid cancer. She was diagnosed the previous September and had a gland removed before being dosed with radioactive iodine. On 29 April 2018, Síle got engaged to long-term partner Damien O'Farrell, which she shares a son Cathal.
