The move means men whose last sexual contact with another man was more than 12 months ago will be free to donate blood so long as they meet the other donor criteria.
The change to policy was announced by Health minister Michelle O'Neill in June.
It brings Northern Ireland into line with England, Scotland and Wales.
Ms O'Neill is lifting the ban in favour of a '"one-year deferral system" as is the case in the rest of the UK.
This means that gay and bisexual men can give blood one year after their last sexual contact with another man.
Ms O'Neill said patient safety remained paramount.
"As health minister my first responsibility in this matter is patient safety," she added.
"Surveillance data from England, Scotland and Wales and survey evidence from across Britain and the north of Ireland have provided assurance that the risk is lower with a one-year deferral.
"My decision is based on the evidence regarding the safety of donated blood."
The change will be implemented by the Blood Transfusion Service from Thursday and means the criteria will be in line with other groups who are deferred from giving blood for 12 months due to infection risks associated with sexual behaviours.
The minister said blood donors "save lives every day" and the "need is constant".
She added that the blood service in Northern Ireland "is carefully managed to maintain a safe and sufficient supply of blood for transfusions".
"The safety of donated blood depends on two things: donor selection and the testing of blood," she added.
"Every blood donation is tested for HIV and a number of other organisms. Not even the most advanced tests are 100% reliable, so it is vitally important that every donor complies with all the donor selection rules.
"These rules are in place to protect the health of donors and of patients who receive blood transfusions."
Previously in Northern Ireland, any man who had sex with another man was banned from giving blood permanently.
A ban on gay men donating blood was brought in across the UK during the 1980s AIDS crisis, but was lifted in England, Scotland and Wales in November 2011.
Northern Ireland's lifetime ban on gay men donating blood is to be lifted on Thursday.