The study, carried out by the Oxford Internet Institute (OII), showed that those aged between 40 and 69 were the most likely to use online dating sites, as 36 per cent of those questioned in that age group revealed that they had found their current partner on the net.
And the findings show that almost one in three internet users admitted to having visiting online dating websites at some point in their lives.
The international survey of 12,000 couples found that just six per cent had gone to dating websites in 1997, but by 2009 30 per cent of the sample had tried them, with 15 per cent finding their current partner that way.
The study also reveals to what extent chat rooms and social networking sites have helped play cupid.
Fewer than 10 per cent of those who began their relationship before 2000 said they had met through such means but by 2005 it had doubled to 21 per cent.
The findings dispel the myth that social networking and online dating is primarily for the young, just 23 per cent of 18- to 40-year-olds saying they had started a relationship through the internet.
Meanwhile, only two people in the sample said they had started a relationship in their 70s and neither did this through the internet.
The online questionnaire, which quizzed couples from 18 countries, all of whom had regular access to the internet, asked a series of questions about whether they had visited dating websites, other online services and where else they might go looking for a partner. The questions related to the period 1997 to 2009.
But most people still said they had met their partner through traditional offline channels