Whether it is modern slavery or slavery in its modern form, there is evidence that some practices continue to deprive some human beings of their basic human rights and freedom, which has become a matter of concern in recent decades across the world, despite attempts to eradicate it. This article examines the forms of modern slavery and the pertinence of the ongoing debate about the phenomenon in Nigeria and the United Kingdom. This shows that modern slavery is practiced in ways that are unknown to the general public and authorities alike. The article then evaluates the underpinning factors that drive this practice in Nigeria and the United Kingdom. The article also shows a link between Nigeria and the United Kingdom in promoting the practice since Nigerian human trafficking networks often provide modern slaves to underground slave masters in the United Kingdom. Furthermore, the article demonstrates that while this practice is motivated by economic gain, it has a negative impact on the socio-economic environment of Nigeria and the United Kingdom. The article shows that the practice thrives and perpetuates due to a lack of compliance with international and domestic legal instruments in terms of implementation and enforcement of the law. Therefore, the article concludes that the need for law and policy responses must be accompanied by other measures to eradicate the deeply rooted phenomenon in Nigeria and the United Kingdom.