The actor has launched a fundraising campaign for the British Red Cross on JustGiving, with the aim of raising £15000 for the victims of the attack and their families.
Writing on the page, Hardy described the attack as an "inconceivable atrocity".
What happened at the AG [Ariana Grande] concert in Manchester was a tragedy; families and children attacked and murdered; in a place where they should be safe and enjoying a concert – it is an inconceivable atrocity. There is no bringing back those who have been lost, pointlessly, in such a cowardly and brutal fashion. I am truly saddened by what I have witnessed and there is no doubt that Terrorism is an evil thing.
Hardy went on to state that he wants to help repair the lives of those affected by the attack.
I hope that between us we can raise some funds as a gesture of goodwill and love to help in some small way towards repairing some if any of the damage down. There will be much to do and for many the beginning of a new life without those that they love and also a new life damaged irreovcably by the actions of a crime which has no reason, no heartfelt purpose but was simply a cruel cowardly and barbaric, meaningless act of violence.
He concluded by sending his "heartfelt concern and deepest sympathies" to all the victims and witnesses.
Terrorism is abhorrent, the killing of innocent families and children unacceptable. And it is with those, the innocent victims and witnesses of this atrocity that my heartfelt concern and deepest sympathy lies. Please help however you can. Thankyou.
An outpouring of public support has seen 150 JustGiving fundraising pages launched since the attack on Monday night.
Fundraising initiated by the Manchester Evening News led to over £1 million in donations in just 24 hours. Since then, the total across all 150 pages has climbed to £2 million. The money will be rolled into the British Red Cross's "We Love Manchester Emergency Fund" to help the victims and their families.