Her media career began embryonically before she left school, when at the age of 14 she presented a one off programme to raise money for Comic Relief on the BBC Local Radio station, BBC WM. She graduated from university in Hertfordshire in 1994 with a degree in Humanities.
On her show on the BBC Asian Network she has said a number of times that she was married for some years as part of an arranged marriage, but that she subsequently got a divorce and is going to choose who, if anybody, she marries in future herself.
On 6 October she was the co-host, with then Director-General of the BBC, Greg Dyke, of the BBC local radio's Frank Gillard Awards ceremony held at the National Museum of Photography, Film and Television (now renamed the National Media Museum) in Bradford. In an interview with The Independent newspaper in May 2006, Deol would state that co-hosting the awards with Dyke was one of the proudest achievements in her working life. Her show won a bronze award in the Interactive Category of the 2003 Sony Radio Academy Awards.
In May 2004 the BBC Press Office had to deny that Deol had been sacked over an "on-air blunder" on the Sonia Deol Show. A guest on the show had said that that Guru Nanak Dev, the founder of Sikhism who is also revered by Hindus and Sufi Muslims, was Satan, resulting in a huge backlash and even a campaign to boycot the Asian Network. Although Deol had immediately informed the guest how offensive their remarks were, the BBC had to release a statement to make it clear that the views expressed by the guest were "deplorable and condemned by the programme makers and the management of the Asian Network". The national dual-language Sikh Times ran a front page article expressing its disgust at the Asian Network. In May 2005 she presented her show live from a temporary "mini radio station" at the St Paul's Way Community School in Tower Hamlets, London as part of a series of broadcasts from the school to celebrate the first visit to England of the Bangladesh national cricket team. On 2 September she presented her show live from Paris, France, one year on from the ban on wearing headscarves and religious symbols in French public schools, often known as the French headscarf ban, looking at the impact the ban had on the Asian community in France and whether the wearing of religious symbols should be banned in British schools.
On the BBC Asian Network her mission has been to broaden the appeal of the network and encourage listeners from backgrounds other than South Asian while maintaining a service to the core audience. On her programme she has talked to all the main British political party leaders and many other leading figures from politics, media, films, music and other areas from around the world.
On 18 November she was nominated in the Best UK Asian Radio Show category in the annual UK Asian Music Awards which was held at the Hammersmith Palais in London on 6 December. The award was won by BBC Radio 1 duo Bobby and Nihal for their midnight show on the station. She won the Asian Achievers Media Award for 2006.
On 24 November 2006 she conducted an exclusive interview for her show, which was later repeated on BBC Radio 4's Today Programme, with long term prisoner in Pakistan, Mirza Tahir Hussain, from Leeds, who had been released from prison after his death sentence had been commuted to life imprisonment by Pakistan President Pervez Musharraf after many years in which Hussain had been found innocent twice and found guilty by different courts and sentenced to death by hanging numerous times. Deol spoke with him on his return to the UK. Deol hosted a special Asian Network Report - Big Brother special debate, broadcast live from the University of East London following on from the Celebrity Big Brother racism controversy. As part of the 2007 Diwali celebrations on 9 November, Deol presented a Diwali special on her morning show, which included her talking with English R&B singer, Jay Sean in the studio about his Diwali plans.
She was a roving reporter on The Heaven and Earth Show on BBC One interviewing the likes of Olivia Newton John former Labour Member of Parliament, Clare Short. In September 2007 she began as working as the telephone calls presenter on its successor The Big Questions, a Sunday morning debate show, presented by Nicky Campbell, also on BBC One, but after 11 weeks stopped appearing on the show. This was initially explained in the following three weeks as being due to illness, but she has not returned to the show, though has instead been appearing as a relief presenter on BBC Breakfast at the weekend. She has also presented the West Midlands regional opt-out for The Politics Show each Sunday on BBC One.