The findings are based on a large-scale study of more than 1,000 randomly selected households in the UK, coupled with regular face-to-face interviews with more than 200 teenagers and their families between 2008 and 2011.
While the study reflects a high level of parental anxiety about the potential of social networking sites to distract their offspring, and shows that some parents despair at their children's tendency to multitask on mobile devices.
However, the research by Oxford University's Department of Education concludes that there are substantial educational advantages in teenagers being able to access the Internet at home.
"Teenagers who do not have access to the Internet in their home have a strong sense of being 'educationally disadvantaged," according to the study.
Researchers found that teenagers felt shut out of their peer group socially and also disadvantaged in their studies as so much of the college or school work set for them to do at home required on-line research or preparation.
"While it's difficult to state a precise figure for teenagers without access to the Internet at home, the fact remains that in the UK, there is something like 300,000 young people who do not - and that's a significant number," researcher Rebecca Eynon said.
"Behind the statistics, our qualitative research shows that these disconnected young people are clearly missing out both educationally and socially," Eynon said in a statement.
The study contradicts claims that others have made about the potential risks of such technologies adversely affecting the ability of teenagers to concentrate on serious study.
Dr Chris Davies and Eynon, found no evidence to support this claim. Furthermore, their study concludes that the Internet has opened up far more opportunities for young people to do their learning at home.
"Parental anxiety about how teenagers might use the very technologies that they have bought their own children at considerable expense is leading some to discourage their children from becoming confident users," Davies said.