The Equality Commission says the figures come from government research into students in further and higher education in Ulster, where the number of people facing homophobic harassment is said to be higher than Britain or the Republic of Ireland.
The commission says the law should be strengthened to give gay and lesbians the same protection as workers enjoy against sectarian discrimination in the workplace. Evelyn Collins, chief executive of the commission, said:
"The consequence of prejudice and discrimination is invisibility, inhibition and lack of trust."
Unlike other anti-discrimination laws in Ulster, sexual orientation legislation does not cover provision of goods, facilities, services and accommodation.
Ms Collins, who addressed a conference in Belfast, said the abuse and bullying led to reduced attainment and a high-drop out rate for gay students. She said providers should have measures in place to prevent discrimination and to deal with any complaints "promptly and effectively".
She said those affected may be unwilling to complain but warned that silence on the subject did not mean there were no problems.