Osarobo 'John' Izekor (36) and his 29-year-old wife Precious Izekor were both handed a two-year prison sentence, which was suspended for two years, by Judge Richard Greene QC.
The couple - who have three children - were also ordered to pay the woman £10,000 in compensation.
Today's sentencing at Belfast Crown Court marked one of the first cases brought under the Human Trafficking and Exploitation Act (NI) 2015.
The husband and wife, with an address at Ashmount Gardens in Lisburn, admitted that on dates between September 1, 2016 and September 30, 2017 they 'required another person to perform forced or compulsory labour.'
Whilst the victim was forced to carry out domestic duties, a majority of the criminality by the Izekors was unpaid childcare in their then Castlereagh Place home in Belfast.
As he sentenced the couple, Judge Greene said that whilst it was accepted the Izekors did not physically ill-treat the women they kept as a domestic slave, they gained financially by not having to pay childcare costs while they worked.
The judge added there was also a financial loss to the victim and spoke of the "exploitation of her in the excessive hours she was required to work - both in childminding and in doing household chores which she ought not to have been asked to perform."
The victim - who is now 33 - arrived in Northern Ireland in 2011 and worked as a nanny for a five-year period.
When her employer sister returned to Nigeria in the autumn of 2016, the woman moved into Castlereagh Place with the Izekors. During this period, she was kept ignorant of her immigration status and was prevented from having access to her passport and paperwork.
Whilst working for the Izekors, the woman had her own room and was given food and clothes but was not paid any money, while a small sum was sent to her family in Nigeria.
When she finally raised the issue of her documents with Precious Izekor, an argument ensued. A few days later, she left the Izekors and went to stay with a friend, who - concerned for the woman - felt she was being exploited and accompanied her to the Home Office.
When a Home Office official called at the Izekors' home, Precious was asked about the woman, and denied knowing her.
An investigation was launched which resulted in the involvement of the PSNI and the arrests of John and Precious Izekor, who both admitted the offence.
Crown prosecutor Charles MacCreanor QC said the Probation Board had assessed both husband and wife of presenting a medium risk of re-offending, and both had displayed a limited victim awareness.
Mr MacCreanor said John Izekor possessed a "distorted view of the power relationship" between him and the domestic slave, while Precious has maintained the view that she was helping the woman out.
Pointing out their offending was "over a protracted period", the barrister added both John and Precious Izekor "had a good working knowledge of the immigration system and have abused it."
Gavan Duffy QC, representing Precious Izekor, told Judge Greene that the couple's Lisburn home was attacked last week.
He told the court: "Unfortunately last Thursday evening, in the middle of the night, a mob attacked the home of the defendants where they live with their three children.
"Very significant damage was caused to the property, the children were terrified by what was taking place.
"Police officers were called to the scene and the defendants and their children had to be escorted away from their home to a safe place and now, as a consequence of that, they are now homeless."
Mr Duffy pointed out that his client was not responsible or involved in any way in bringing the woman to the UK. He also said that during the offending period, there were no threats or violence, there has been no further contact with the woman and there has been no further offending in the five years since her arrest.
John Izeokor's barrister Barry Gibson said his client was a "highly skilled individual" with a degree in accountancy and two business-related post graduates.
As the defendant stood in the dock, Judge Greene said: "He is a man who professes to have Christian values.
"How someone can have Christian values and treat someone like this is beyond me. Perhaps he will reflect on those Christian values in the years ahead."
After passing sentence and ordering them to pay their victim £10,000 compensation, the couple were told by the Judge "you are now free to go."