Mary Byrne (born 3 November 1959) is a top 10 selling Irish singer and TV presenter based in Ireland and the UK. Mary rose to fame in 2010 after becoming a contestant on the seventh series of The X Factor. After being the twelfth contestant eliminated finishing in fifth place, she signed a record deal with Sony Music Ireland. Byrne and her fellow The X Factor finalists gained a number-one single on the UK Singles Chart and the Irish Singles Chart with a cover of David Bowie's "'Heroes'" in aid of Help for Heroes.

She was also Neil Diamond's special guest at the Aviva Stadium, where she performed in front of 55,000 people. In August 2011, Byrne appeared in GREASE: The Musical at the Grand Canal Theatre in Dublin. She began work on an autobiography, This Is My Life, and was released on 21 October 2011 in the UK and Ireland. Mary decided to leave Sony Music as she accepted a new record deal offer with Decca Music and Universal Music, who are confident they can "get her music career up and off the ground". She has produced her second album, called ...with Love. In 2012, Byrne appeared on Celebrity Bainisteoir. Mary was also the main presenter on 3 networks panel show Midday, a show that aired live weekdays in Ireland and follows a format such as the ITV series Loose Women. She was also a co-presenter on the talk show Elaine Crowley.

Byrne suffered from arthritis in her knees which proved difficult for her during the initial stages of The X Factor, but has led to comical improvisations during her tour with Grease. Before The X Factor, she worked for supermarket chain Tesco, leading to her referral as "Tesco Mary".^{[citation needed]} She quit singing at 28 because of low self-esteem after a failed relationship. After her appearance on The X Factor she admitted on RTÉ's The Late Late Show that she had suffered from clinical depression for a number of years. She performed with her brother, Tommy, under the name The Tommy Lee Experience. In 2008 she won the Irish television singing contest Nollaig No. 1 using the name Mary Lee and released the single "Siúil Leat".

Byrne entered reality television show The X Factor in 2010. Her employer, Tesco Ireland, started a campaign to persuade all staff to support her. Byrne advanced to the live shows and was mentored by Louis Walsh in his Over 28s category. On the first live show, Byrne gained the most public votes by singing "It's a Man's Man's Man's World". Byrne's song "I (Who Have Nothing)" that was successful in Dublin was a relief to Walsh as Simon Cowell was annoyed with him for wanting to stage the auditions there. Byrne was in the 'Final Showdown' twice. In the quarter-final, she was in the Bottom Three with fellow contestants Wagner, and Katie Waissel. As Waissel received the fewest votes she was eliminated first and competed against Wagner in the final showdown. Byrne advanced to the semi-final after Walsh, Dannii Minogue and Cheryl Cole voted to send Byrne through to the semi-final. Although Simon Cowell was not required to vote as there were already three of the four judges voted to send Byrne through to the semi-final, he confirmed that he would’ve also voted to send Byrne through to the semi-final. However, in the semi-final, Byrne was in the bottom two with Cher Lloyd and was eliminated with only her mentor, Walsh voting to send Byrne through to the final, who was the twelfth contestant eliminated. After the series finished, voting statistics revealed that Byrne received more votes than Lloyd. This meant that if there was not a Final Showdown, or if Minogue or Cowell voted to send Byrne through to the final or if the result to deadlock, Byrne would've advanced to the final and Lloyd would've been eliminated.

Following her career on The X Factor, Byrne signed a record deal with Sony Music Ireland and began work on her debut album. The album, Mine & Yours, was released in the UK on 28 March 2011, and 25 March in Ireland. Byrne released her debut single, a cover of Martina McBride's "I Just Call You Mine", due to phenomenal demand when the track was debuted from her album Mine & Yours on Irish radio. The fan reaction was so positive that Sony Music Ireland were 'inundated' with requests to make the song available to the public and 'eager fans' prior to the album's release. After little to no promotion, the song peaked at number 12 on the Irish Singles Chart. Byrne revealed her album would be sold on QVC like Susan Boyle did to help sell a few more copies. In an interview with Digital Spy Byrne stated;

Recording this album was a dream come true. I'm so grateful for all of the support I received both during and after the show. Nothing I'm experiencing now would have been possible without the wonderful people who picked up their phone each weekend and voted for me! I hope you enjoy listening to the album as much as I enjoyed making it.

— Mary Bryne in an interview with Digital Spy

The album was produced by hit-maker, Nigel Wright and contains tracks which Mary performed on The X Factor. However, the songs on the album are not her performances from the show. Byrne was on the 2011 The X Factor Live Tour, and Sony Music began planning Byrne's first solo concert tour before she decided to move onto Universal music. Mine & Yours debuted at number-one on the Irish Album Charts on 31 March 2011.