The European soccer body said the decision followed what it described as a successful pilot match on Sept. 24 where Bayern Munich faced Sevilla in the Super Cup in Budapest.
Apart from that game, UEFA has staged all matches behind closed doors due to the COVID-19 pandemic since the restart of football in June.
UEFA said the admission of fans and the capacity limit would be subject to the decision of local authorities.
It said that matches cannot be played with spectators where local authorities do not allow it and that the limit of 30% may be reached if the limit set by local authorities is not lower.
It added that away fans would not be allowed, that social distancing will be mandatory for spectators and additional precautionary measures such as the wearing of masks must be implemented according to local rules.
“The UEFA Super Cup demonstrated that it is possible for fans to attend football matches in the right circumstances by putting their health and safety first with comprehensive mitigating measures in place,” UEFA said.
UEFA president Aleksander Ceferin said that 27 countries in Europe already allowed fans in stadiums to some degree.
“(The) decision is a sensible first step which puts fans’ health first and respects the laws in each country,” he said.
“This decision allows much more local flexibility to deal with admitting fans than was previously the case, always respecting the assessment of local authorities.”