Ipsos Mori found 30 per cent of people said religion is important to them, a figure significantly lower than the global average of 53 per cent.
The statistics place Britain among the least religious countries in the world, with only Sweden, Belgium and Japan ranked lower.
The survey, which polled 18,000 people across 23 countries, also found four in five Britons believe the country has become more hostile towards immigration.
It concluded fewer than one in ten people believe healthcare will improve in future.
According to the 2011 census, 14.1 million - around one in four - people in England and Wales reported that they had no religion.
While the proportion of the population who identify as Christian declined from 72 per cent in 2001 to 59 per cent in 2011, all other main religious groups - including Islam - grew.