Up to 13,000 fans will attend the Uefa Super Cup between Chelsea and Villareal at Windsor Park in Belfast on 11 August.
With the venue allowed to operate at 70% of its maximum capacity, it will be the biggest crowd to attend a sporting event in Northern Ireland since before the first lockdown in March 2020.
The decision was made after talks between the Irish FA, Uefa and the NI Executive, who also reached an agreement that travelling Villareal fans will not have to self-isolate.
All spectators will be asked to show proof of double vaccination or provide a negative Covid-19 test on entry.