The study, published in the Journal of Population Economics, has found that homosexual and bisexual men take home nearly £1,500 less per year than heterosexual men.
Researchers from Anglia Ruskin University (ARU) analysed 24 studies published between 2012 and 2020 covering countries in Europe, North America and Australia.
In America, the number doubles, with homosexual and bisexual men earning 10.7 percent less than their heterosexual counterparts.
On average across Europe, North America and Australia, homosexual men earn 6.8 percent less on average than heterosexual men while bisexual men earn 10.3 percent less.
The study also looked at bisexual and homosexual women. In the UK, it found that the former earn 5.1 percent less than heterosexual women.
However, lesbian women on average earn 7.1 percent more than heterosexual women, the study found.
The researchers called the findings “a cause for concern”.
In the UK, workplace prejudice against individuals due to their sexual orientation or sex is prohibited under the Equality Act of 2010. However, despite this legislation, the research suggests that gay men and bisexual men and women still earn less than their heterosexual counterparts.
Professor Nick Drydakis, author of the study and Director of the Centre for Pluralist Economics at ARU, said: “Legislation and workplace guidelines should guarantee that people receive the same pay, and not experience any form of workplace bias simply because of their sexual orientation or gender identity status.
“Inclusive policies should embrace diversity by encouraging under-represented groups to apply for jobs or promotions and providing support to LGBTIQ+ employees to raise concerns and receive fair treatment.
“Standing against discrimination and celebrating and supporting LGBTIQ+ diversity should form a part of HR policies.”