Public buildings across the country will fall silent at 2.30pm today (Tuesday 22 May) midway through a national service of remembrance at Manchester Cathedral due to be attended by Prince William and the Prime Minister.
The silence will be observed outside the Force's Devizes HQ.
Chief Constable Kier Pritchard said: "We are pausing to remember the 22 people who went to a pop concert in Manchester a year ago and lost their lives.
"A number of the victims were children who had been enjoying a performance by Ariana Grande.
"Among them was eight year old Saffie Roussos, described by her head teacher as 'simply a beautiful little girl in every sense of the word'.
"Many more people were injured when Salman Abedi detonated a home-made bomb in the Manchester Arena as the concert was ending.
"Wiltshire Police responded without hesitation to a call for support from Greater Manchester Police. We swiftly despatched eight officers as part of the national programme of mutual aid.
"In the days that followed the carnage at Manchester Arena, our officers - alongside colleagues from many forces - provided reassurance to the people of the city.
"They were also on duty to look after the safety of tens of thousands of fans at two concerts at the Etihad Stadium in the city and at a special tribute concert.
"It's an example of the work that goes on 'beyond the beat' to help colleagues in other parts of the country at a time of crisis.
"One year on, we are gathering to remember those who died, those who were injured, and their loved ones."
Angus Macpherson, Police and Crime Commissioner for Wiltshire and Swindon, said: "The terrible events in Manchester a year ago created a sense of shock across the country because the bomber struck at the end of a pop concert which had been enjoyed by thousands of children and young people.
"There were many stories of heroic behaviour by the emergency services and the public after the explosion. Despite fears that there might be a further attack, police officers ran into the arena as concert goers were running away.
"We can be proud that Wiltshire Police officers were deployed quickly to Manchester and that they spent days in the city, helping to reassure the public and keep them safe.
"By observing the national silence, we can stop and reflect on the lives tragically cut short that evening; on those who lost loved ones; and on the police, the paramedics and others who witnessed such ghastly scenes as they fought to save lives."
One of the Wiltshire officers despatched to Manchester was Det Sgt Adam Leakey, who is based at Gablecross Police Station in Swindon. He was deployed to the Etihad Stadium.
He recalled: "Our duty was to provide community reassurance to the 50,000-strong crowd attending two Robbie Williams concerts; assisting stewards with bag searches and ensuring the fans dispersed safely and quickly."
Sgt Liam Winstone, of Swindon South Community Policing Team, was also deployed to the Etihad Stadium.
He said: "The response from the public at the concerts was incredible. I have never been thanked so much for just being there and doing my job.
"I felt a little embarrassed to receive this praise and made a point of informing the public that I was from Wiltshire and it was the Greater Manchester Police officers they needed to thank. The response was that they were thanking us all for the job we did.
"As the crowd was leaving the stadium at the conclusion of the Saturday evening concert, we received news of the attack on London Bridge. We managed the safety of the crowd firmly and empathetically, ensuring that we did not raise alarm.
"It wasn't hard to work out that the London Bridge attack would impact on the One Love benefit concert planned for Old Trafford cricket ground in Manchester the next day as a tribute to those who died in the bomb attack.
"We had been due to depart, but I canvassed the team and everyone was in agreement that we should stay.
"Our area of responsibility covered the artistes and VIP entry but, more importantly, the entry that those injured at the Manchester Arena bombing would use. They arrived in a fleet of buses.
"On each occasion we had to stop the crowds heading into the stadium to enable the buses to pass. As soon as the waiting public realised who these people were there was applause.
"Several of the survivors were in wheelchairs. It was quite emotional to see how brave they were going into the concert, considering the trauma they had suffered.
"We received information that there was a suspicious man in the queue. I was tasked, along with my Wiltshire colleague Martyn Cole, to pinpoint the suspect and check him out.
"Having watched him for a few moments he was definitely acting suspiciously. We approached and secured him, removing him swiftly from the queue and away from the public gaze before searching him.
"It turned out that he was trying to blag his way into the concert with no ticket.
"We returned to Swindon, but were called back to Manchester several days later to carry out high visibility patrols in the city centre to reassure the public.
"Every shop window displayed an 'I ❤MCR' poster. There was a real community spirit and almost a bullish attitude that everyone was carrying on.
"PC James Rodrigues and I walked into St Ann's Square which was carpeted with floral tributes. It was very sobering to stand in silence with many other people, looking at the huge swathe of flowers.
"The reaction of the Manchester public towards us was very warm, even more so when they learned where we were from."
PC Steve Carroll, from the Wiltshire North Community Policing Team based in Royal Wootton Bassett, was born at Salford in Greater Manchester.
In the aftermath of the attack he presented a shield with the inscription "Together We Stand" to an assistant chief constable at Greater Manchester Police as a symbol of solidarity.
He and his Wiltshire North colleague PC Jamie Ball also visited St Ann's Square.
PC Carroll said: "It was surreal - a peaceful moment on a normally very vibrant, busy street. "We just stood in silence and appreciated all the love that Manchester has got. How the city came together was amazing."