The Lord Mayor of Belfast, Gavin Robinson announced on Monday that the campaign had been successful and the target had been raised through public fundraising and local events.
"It is wonderful to be able to make this announcement on behalf of the four charities involved in the Children`s MRI Scanner Appeal," he said.
"The success of this appeal can be directly attributed to the generosity of the Northern Irish public as the public's fundraising and donations have raised the entire £2m needed.
"An MRI Scanner will increase the access to MRI for sick children in Northern Ireland and many more children will be able to benefit from this treatment as opposed to undergoing different types of investigation which may be invasive or involve radiation."
The charities that joined together for the Children's MRI Scanner Appeal include Helping Hand, Carrickmannon MRI Scanner Children`s Appeal, the Northern Ireland Children's Cancer Unit Fund and the Children's Heartbeat Trust.
The Royal Belfast Hospital for Sick Children has been the only children's hospital in the UK and Ireland not to have an MRI scanner, and this purchase will help in the treatment of sick children at the hospital.
Sarah Quinlan, Executive Officer of the Children's Heartbeat Trust, said: "The achievement of meeting the £2 million target is a huge success for the Children's MRI Scanner Appeal. It means that the Royal Belfast Hospital for Sick Children can now obtain an extremely important machine, stopping the need to take difficult transfer to the adult facility in the hospital.
"On behalf of the four charities I would like to thank everyone who supported the Children`s MRI Scanner Appeal."
Another £2.75m of funding for the scanner was announced by the Health Minister Edwin Poots in November at the Royal Does Strictly event, which featured UTV's Alison Fleming and Marc Mallett.
The event raised more than £100,000 for the appeal after two sell-out nights.