Health officials say the HPV vaccine for 12 to 13-year-old boys, starting after the summer, will prevent 29,000 cancers in UK men in the next 40 years.
The boys will be eligible from the start of the new school year, 11 years after girls were first vaccinated.
The jab protects against human papilloma virus, which causes many oral, throat and anal cancers.
Girls aged 12 to 13 have been offered the HPV vaccine since 2008 in the UK.
Two doses are needed to be fully protected. Protection lasts for at least 10 years, although probably much longer.
Why are boys now getting the jab?
Because the programme to vaccinate teenage girls, and reduce cervical cancers, has proved very successful.
There has been a reduction in HPV infections,genital warts and pre-cancerous growth in teenage girls and young women since the vaccine was introduced.
Other groups, like teenage boys, have seen benefits too because the virus is not being passed on to them.
To protect boys even more, and reduce cancers of the anus, penis, head and neck in the future, health experts say they should be offered the HPV vaccine too.
Why is it needed at that age?
The HPV vaccine works best if boys and girls get it before they become sexually active.
High-risk HPV infections can be spread by any skin-to-skin contact, and are usually found on the fingers, hands, mouth and genitals.
This means the virus can be spread during any kind of sexual activity, including touching.
What about older boys?
Boys who are 14 to 18 will not be able to get a free, catch-up vaccine in the UK – but they can buy it for around £150 per dose.
Health officials say that boys are already benefitting from protection from the girls’ HPV vaccination programme and this has reduced the spread of the virus.
Girls can continue to have a catch-up jab up to the age of 25.