Kelly was born in the Gorbals area of Glasgow, Kelly’s father, John, worked as a television repairman. She spent the first few years of her life in Glasgow before the family moved to East Kilbride where she attended Claremont High School. She turned down a university place to study English and Russian in favour of a job on the East Kilbride News, her local newspaper, and then joined BBC Scotland as a researcher in 1983. She moved to TV-am as an on-screen reporter covering Scottish news in 1984.

In early October 1984, Kelly joined TV-am as Scotland Correspondent. On the back of her coverage of the Pan Am Flight 103 disaster in Lockerbie, in July 1989, Kelly presented TV-am’s Summer Sunday programme with chief reporter Geoff Meade. Throughout the rest of 1989, provide cover for the presenters on the main weekday programme. On 31st January 1990, she became a main presenter of Good Morning Britain alongside Mike Morris.

In April 1991, Kelly was awarded the TRIC Diamond Jubilee Award for New Talent of the Year. In 2004, she was elected as the first female rector of the University of Dundee, being formally installed to office on 28 April 2004. She held this position until 2007. On 20 June 2008 she was awarded an honorary Doctor of Laws from the university for her services to charity. On 28 June 2018 She was awarded the Honorary degree of Doctor of Arts from Edinburgh Napier University.

In January 1993, Kelly helped launch GMTV by presenting a range of programmes. Her first job was presenting the new Top of the Morning. In March, when Fiona Armstrong walked out of the main GMTV show, Kelly moved to the main breakfast show with Eamonn Holmes. In June 1994, Kelly went on maternity leave, but shortly afterwards she was sacked from the main presenting roles, she returned in November 1994 to do a mother and baby slot. This led to her becoming the presenter of Nine O’Clock Live. The show proved so popular that it was moved to the earlier 08:35 slot, retitled Lorraine Live.

Between 1993 and 2005, Kelly lived at Cookham Dean in Berkshire, outside London, with her husband, television cameraman Steve Smith, whom she married in 1992. Kelly previously lived in Broughty Ferry, Dundee until December 2017 as she found commuting back and forth was not working, Kelly and her husband then decided to sell their Broughty Ferry home to be closer to Lorraine’s work, and so they could spend more time together. Kelly has described herself as an ‘adopted Dundonian’ and despite moving away, she considers Dundee to be a place that she will always call home.

They have one daughter, Rosie, born in 1994. Kelly was born to a Catholic mother and a Protestant father, but she is an outspoken critic of Catholic schools in Scotland and has called for an end to them saying they were a cause of trouble in society, and prolonged the “scandal of sectarianism”.

In Autumn 2000, as GMTV rebranded to GMTV Today, Kelly’s show changed its name to LK Today. As part of the later rebrand that took place in 2009, the show again changed its title to GMTV with Lorraine, to coincide with GMTV Today changing back to GMTV. Lorraine moved for the first time into the main GMTV studio, instead of Kelly having her own part of the studio to host from. In April 2010, to make GMTV’s programming more consistent, GMTV with Lorraine began airing all year round, instead of breaking during school holidays, with guest presenters.

During 1994/1995 Kelly also presented Carlton magazine programme After 5. She appeared on Lily Savage’s Blankety Blank in 2001.

Kelly presented Liquid News, the spin-off Liquid Eurovision and became the national spokeswoman for the United Kingdom during the collation of votes at the Eurovision Song Contest, in both 2003 and 2004, replacing the long-serving Colin Berry.

From 2004, Kelly co-presented This Morning with Phillip Schofield, on Mondays and Fridays, to allow Fern Britton to spend more time with her family, but she left in March 2006.

Kelly hosted the annual Glenfiddich Spirit of Scotland Awards in 2005 and 2006 for STV.

Kelly also hosted the annual Glenfiddich Spirit of Scotland Awards in 2005 and 2006 for STV.

In 2006, Kelly filmed an ITV documentary programme Secrets Revealed – DNA Stories, made by STV Productions, and broadcast on Sky Real Lives. A second series was shown on the channel in 2008.

According to the Sunday Mirror, in 2007, Kelly was prevented from appearing in an advertising campaign for Asda as GMTV managing director Clive Crouch felt that such a move would create more bad publicity for GMTV, which had recently been fined £2 million by broadcasting regulator Ofcom for its misuse of premium-rate phone lines.

In November 2009, ITV plc took full control of the broadcaster after purchasing The Walt Disney Company’s 25% share. On 9 July 2010, as well as the announcement that GMTV had been axed to make way for Daybreak, it was also revealed that Kelly’s new programme Lorraine would replace GMTV with Lorraine On 15 July 2010, Kelly presented her last show before leaving.

Kelly writes weekly columns for The Sun and The Sunday Post. She was announced as the first Agony Aunt for the Royal Air Force’s fortnightly RAF News on 7 October 2009.

Since June 2009 she has been an Honorary Colonel in the Black Watch battalion Army Cadet Force. Since November 2019, she has been National Honorary Colonel of the Army Cadet Force.

On 6 September 2010, GMTV ended with ITV Breakfast taking over. Lorraine launched with a brand new look, alongside Daybreak.

In 2010, Kelly filmed a six-part documentary series Lorraine Kelly’s Big Fat Challenge shown on Bio. The series featured Kelly and a team of experts putting ‘Britain’s fattest family’, the Chawner family through their paces to lose weight and transform their lives. Daughter Emma Chawner is best known for her unsuccessful appearances on The X Factor.

In 2010, in conjunction with the Missing People charity, Sky and STV produced a new documentary series hosted by Kelly, about missing mothers. This series followed the success of Sky’s previous successful missing person series Missing Children: Lorraine Kelly Investigates.

In 2011, Kelly presented the ITV series Children’s Hospital, and was a guest presenter on the BBC Two series Never Mind the Buzzcocks in series 25. She provides voice-over and narration on the CBeebies show Raa Raa the Noisy Lion.

Since 2011, Kelly has hosted STV’s Children’s Appeal annually with Sean Batty, she also hosts STV Appeal Stories on the channel and her 2016 Show Lorraine & Friends.

In 2011, Kelly was among the celebrities to take part in the BT Red Nose Desert Trek which took place in the Kaisut Desert for Comic Relief and raised £1,375,037.

She has been an ambassador and presenter for STV Children’s Appeal since its creation in 2011. Kelly also became an ambassador for the charity Sightsavers in 2011.

On 4 May 2012, it was confirmed that Kelly would take over from Christine Bleakley as presenter on Lorraine’s sister programme Daybreak. She debuted on 3 September 2012. She co-hosted the programme with Aled Jones from Monday to Thursday, with Kate Garraway co-hosting on Fridays.

Kelly was appointed Officer of the Order of the British Empire (OBE) in the 2012 New Year Honours for services to charity and the armed forces and was promoted to Commander of the Order of the British Empire (CBE) in the 2020 Birthday Honours for services to broadcasting, journalism and charity.

In February 2014, Kelly announced that she would leave Daybreak to focus on Lorraine which she began hosting five days a week from 28 April 2014. Daybreak was replaced by Good Morning Britain in April 2014. Lorraine would occasionally report for GMB whenever her show wasn’t aired.

In 2014, Kelly made a cameo appearance in an episode of Birds of a Feather. On 19 September 2014, Kelly reported from Dundee on Good Morning Britain on the Scottish independence result. On 13 April 2016, Kelly guest presented an episode of This Morning with Rylan Clark-Neal.

On 16 November 2014, Kelly received a special Scottish BAFTA award honouring her 30-year television career.

Kelly has been described by Attitude as “one of Britain’s cult gay icons”. In 2015, she was given the “Honourary Gay Award” at the 2015 Attitude Awards for her support for the LGBT community.

Kelly presented a four-part series for Channel 5 called Penguin A&E with Lorraine Kelly. The series began airing on 10 May 2016. In 2018, Kelly co-presented Wedding Day Winners with Rob Beckett. The show aired on Saturday nights on BBC One. In May 2019, she made a cameo in Coronation Street. During the COVID-19 pandemic, she hosted her programme in the Good Morning Britain studio. “Good Morning Britain with Lorraine” had a more news-focused style to it, yet still featured interviews with celebrities, Hollywood updates from Ross King, and medical advice on the pandemic with Dr Hilary Jones. She returned to the Lorraine studio on 13th July.

Kelly hosted the 2014 and 2015 Hogmanay Party which aired on New Year’s Eve just before midnight and after Midnight. Hogmanay Party didn’t continue in 2016 instead Kelly hosted Lorraine Kelly’s Hogmanay.

In 2018, Kelly spoke of her experiences with the menopause, and encouraged other women to speak about it.