The Human Trafficking and Exploitation Bill was voted through at Final Stage and includes legislation to criminalise paying for sex, tougher punishments for those found guilty of trafficking and a statutory support service for victims.
Christian charity Care described it as a 'landmark' moment in the fight against modern day slavery.
The bill is the first dedicated anti-slavery legislation to be passed into law by any UK parliament or assembly in more than 200 years.
It was brought by Lord Morrow and also creates a new offence of forced marriage and will place a duty on the Department of Health, Social Services and Public Safety to provide support for those wishing to leave prostitution.
CARE Northern Ireland Policy Officer Mark Baillie said: "This is a landmark moment in the fight against modern day slavery.
"Northern Ireland has just become the first of the home nations to introduce robust legislation that will tackle human trafficking.
"Lord Morrow's Bill goes significantly further than the UK Government's much trumpeted Modern Slavery legislation in Westminster.
"This Bill not only provides support for victims, as evidenced by the creation of independent guardians for trafficked children and the statutory duty it places on the Department of Health to provide much needed assistance to women wishing to leave prostitution, it also tackles one of the root causes of trafficking, namely paying for sex.
"Lord Morrow has worked tirelessly over the last 18 months to steer the legislation through and the level of dedication and determination he has shown is hugely commendable.
"It is clear there is a growing international consensus to tackle the problem of human trafficking through law and Northern Ireland is now an example for other countries to follow.
"The gauntlet has well and truly been thrown down to the other parliaments across the UK in terms of what is done to tackle the evil of trafficking."
Hear Mark Baillie's interview with Premier's Marcus Jones: