[10] The bombing caused outrage both locally and internationally,[8][11] spurred on the Northern Ireland peace process,[3][4][12] and dealt a severe blow to the dissident Irish republican campaign.

[12] The victims included people of many backgrounds and ages: Protestants, Catholics, six teenagers, six children, a woman pregnant with twins, two Spanish tourists[13] and others on a day trip from the Republic of Ireland.

[17] Colm Murphy was tried and convicted of conspiring to cause the bombing, but was released on appeal after it was revealed that the Garda Síochána forged interview notes used in the case.

[27][28] On 13 August, a maroon 1991 Vauxhall Cavalier was stolen from outside a house at St Macartan’s Villas in Carrickmacross, County Monaghan, Republic of Ireland.

[34] BBC News stated that police "were clearing an area near the local courthouse, forty minutes after receiving a telephone warning, when the bomb detonated.

[33] During the later Special Criminal Court trial of Real IRA director Michael McKevitt, witnesses for the prosecution said that the inaccurate warnings were accidental.

The blast was so strong that it tore up concrete and pipes burst; the water, running down the street, turned red from the blood of dead and wounded people.

[13] Injured survivor Marion Radford described hearing an "unearthly bang", followed by "an eeriness, a darkness that had just come over the place", then screams as she saw "bits of bodies, limbs" on the ground while she searched for her 16-year-old son, Alan.

[44] Sinn Féin's Martin McGuinness said, "This appalling act was carried out by those opposed to the peace process," while Gerry Adams said, "I am totally horrified by this action.

[51] BBC News reported that, "Like the other bombings in the early part of 1998 in places like Lisburn and Banbridge, Omagh was a conscious attempt by republicans who disagreed with the political strategy of Gerry Adams and Martin McGuinness, to destabilise Northern Ireland in that vulnerable moment of hope.

The new measures included allowing suspected members of terrorist groups to be convicted on the word of a senior police officer, curtailment of the right to silence, and longer detention periods.

"[30] Using the phone records, the programme reported the names of the four prime suspects as Oliver Traynor, Liam Campbell, Colm Murphy, and Seamus Daly.

[55] Lawrence Rush, whose wife Elizabeth died in the bombing, tried legally to block the programme from being broadcast, saying, "This is media justice, we can't allow this to happen".

[56] Democratic Unionist Party assembly member Oliver Gibson, whose niece Esther died in the bombing, said that the government did not have the will to pursue those responsible and welcomed the programme.

[46] Builder and publican Colm Murphy, from Ravensdale, County Louth, was charged three days later for conspiracy and was convicted on 23 January 2002 by the Republic of Ireland's Special Criminal Court.

[18] On 28 October 2000, the families of four children killed in the bombing – James Barker, 12, Samantha McFarland, 17, Lorraine Wilson, 15, and 20-month-old Breda Devine – launched a civil action against the suspects named by the Panorama programme.

[59] On 6 September 2006, Murphy's nephew, Sean Hoey, an electrician from Jonesborough, County Armagh, went on trial accused of twenty-nine counts of murder, and terrorism and explosives charges.

[67] In 2021, Michael Gallagher, whose son Aiden was killed during the attack, brought a case to the Belfast High Court which resulted in Mr Justice Mark Horner ruling that when considering certain grounds "there was a real prospect of preventing the Omagh bombing.

[71] The report concluded that, "The victims, their families, the people of Omagh and officers of the RUC were let down by defective leadership, poor judgement and a lack of urgency.

[39][72] RUC Chief Constable Ronnie Flanagan called the report "grossly unfair" and "an erroneous conclusion reached in advance and then a desperate attempt to find anything that might happen to fit in with that.

[75] Kevin Skelton, whose wife Philomena died in the attack, said that, "After the bomb at Omagh, we were told by Tony Blair and the Taoiseach, Bertie Ahern, that no stone would be left unturned ...

[78][79][80] RUC Chief Constable Ronnie Flanagan called the allegations "preposterous" and said the information Fulton gave his handlers was full of "distortions and inaccuracies".

[87] The inquiry will look into four different issues highlighted by a 2021 High Court ruling, namely the handling and sharing of intelligence, the use of mobile phone analysis, the possibility of the existence of advance knowledge of the bomb, and whether the attack could have been prevented by disruption operations.

[94] Michael Gallagher told BBC Radio Ulster that, "The republican movement refused to co-operate and those people hold the key to solving this mystery.

"[94] In January 2002, Gallagher told BBC News that, "There is such a deeply-held sense of frustration and depression" and called the anti-terrorist legislation passed in the wake of the Omagh bombing "ineffective".

[91] Film-maker Paul Greengrass stated "the families of the Omagh Support and Self Help Group have been in the public eye throughout the last five years, pursuing a legal campaign, shortly to come before the courts, with far-reaching implications for all of us and it feels the right moment for them to be heard, to bring their story to a wider audience so we can all understand the journey they have made.

"[91] In promotion for the film, Channel 4 stated that the group had pursued "a patient, determined, indomitable campaign to bring those responsible for the bomb to justice, and to hold to account politicians and police on both sides of the border who promised so much in the immediate aftermath of the atrocity but who in the families' eyes have delivered all too little.

[101] Artist Sean Hillen and architect Desmond Fitzgerald won the contest with a design that, in the words of the Irish Times, "centres on that most primal yet mobile of elements: light.

[100][101] In September 2007, the Omagh Council's proposed wording on a memorial plaque – "dissident republican car bomb" – brought it into conflict with several of the victims' families.

[110] Irish state broadcaster RTÉ and UK network Channel 4 co-produced the 2004 film Omagh dramatising the events surrounding the bombing and its aftermath.