Watkins was once one of Wales’ most recognisable musicians – the frontman of the rock band Lostprophets.
At the height of their fame, the group sold millions of albums around the world.
But the group disbanded immediately after Watkins was convicted in 2013.
Prosecutors described Watkins as a man corrupted by fame, drugs, and power – one who committed crimes “beyond imagination.”
His trial heard Watkins had used his fame to manipulate and control others, often under the influence of hard drugs, including crystal meth.
After Watkins was sentenced, Des Mannion, NSPCC national head of service for Wales, said: “Watkins used his status and global fame as a means to manipulate people and sexually abuse children.
“But we must nevertheless remember that this case isn’t about celebrity, it’s about victims. And those victims are children.”