JJ Hanrahan will join the Dragons this summer from French club Clermont Auvergne.
The Dragons said that 29-year-old Hanrahan, who previously played for Munster and Northampton, had agreed a long-term deal.
Dragons rugby director Dean Ryan told the Welsh region’s official website: “We are delighted that JJ will join us next season.
“JJ will give us added competition for the 10 jersey and brings with him a wealth of experience — from his time at Munster to most recently in France — that will be of huge benefit to our squad.”