The European Medicines Agency has approved the Pfizer/BioNTech coronavirus vaccine for 12 to 15-year-olds, the first vaccine to get the green light for children in the EU.
The vaccine was "well tolerated" in children and there were no "major concerns" in terms of side effects, the Amsterdam-based EMA said.
Germany has said it will start vaccinating children over the age of 12 from 7 June following the authorisation.
The United States and Canada have both already authorised the vaccine for children of the same age.
"As anticipated, the EMA's Committee for Human Medicines has today approved the use of the vaccine from Pfizer/BioNTech in adolescents from 12 to 15 years," said Marco Cavaleri, the EMA's head of vaccine strategy.
Data from clinical trials "is really showing that the vaccine is highly preventative" for young people, he added.
"The vaccine was well tolerated" among children for side effects, and they were "not raising major concerns at this time".
Until now the shot made by US pharmaceutical giant Pfizer and German research firm BioNTech had only been authorised by the EU for people aged 16 and older across the 27-nation bloc.
Pfizer and its partner BioNTech said in March that their two-dose vaccine regimen was shown to be safe and highly effective in a trial of 2,260 12 to 15-year-olds.
EMA chief Emer Cooke had said the watchdog was fast-tracking the approval for young people, which was originally expected in June.
She told European newspapers on 11 May the regulator had received Pfizer-BioNTech data and "we've been promised data from clinical trials and the study carried out in Canada within the next two weeks, and we are going to speed up our evaluation".
Chancellor Angela Merkel announced yesterday that Germany would move ahead with a plan to vaccinate children over 12, pending the EMA announcement.
But she stressed that vaccination would not be compulsory and would have no bearing on whether children can attend school or go on holiday.
Moderna, which also uses the same Messenger RNA technology as Pfizer, said earlier this month its vaccine was 96% effective among those aged 12 to 17, according to the first results of clinical trials.
US health authorities have said they were looking into a small number of reports of heart inflammation among some younger people who received mRNA vaccines such as Pfizer and Moderna.
There were "relatively few reports of myocarditis", primarily in adolescents and young adults, the US Centers for Disease Control and Prevention (CDC) said.
"Most cases appear to be mild, and follow-up of cases is ongoing," the CDC said, adding that reports were more often from males who had received their second dose.