The Working It Out report, commissioned by the Gay and Lesbian Equality Network, and authored by researchers at Trinity College Dublin, also found over 10% of gay workers have quit a job because of discrimination.
The organisation says the report clearly shows why it makes good business sense to address the challenges faced by lesbian, gay and bisexual people in the workplace.
The report highlighted the advantages for employers in attracting LGBT candidates by committing to diversity and inclusion at work.
Of the 590 full-time workers surveyed, two out of three people said they were open about their sexual orientation at work.
Of these, 90% reported a positive working relationship with colleagues.