UEFA announced Thursday it will allow clubs playing in the Champions League and Europa League this season to open up to 30% of their stadiums to fans.
But the governing body emphasized that local authorities will have the final say.
Only supporters of the home team would be permitted and social distancing measures, such as the wearing of masks, would be in effect.
The provision also extends to national teams participating in the UEFA Nations League, which resumes next week.
"Today's decision is a sensible first step which puts fans' health first and respects the laws in each country," UEFA president Aleksander Ceferin said in a statement.
"While we all face a common enemy in COVID, different countries have different approaches and different challenges at any given moment. This decision allows much more local flexibility to deal with admitting fans than was previously the case, always respecting the assessment of local authorities," Ceferin added.
UEFA ran a trial during last week's Super Cup between Bayern Munich and Sevilla, allowing more than 15,000 fans to attend the fixture at the Puskas Arena in Budapest. Roughly 25% of the stadium was in use.
Bayern said fans returning to Germany would have to self-isolate for 14 days. However, most of the tickets were taken by locals.
Fans across Europe are gradually being granted entry to local stadiums despite fears of a second wave of the coronavirus. Up to 1,000 fans have been able to watch games in Italy, while a maximum of 5,000 people are allowed in France.
But other top divisions, like the Premier League, are still waiting for clearance. The British government delayed the return of fans due to a sharp rise in COVID-19 cases in the country.