The Britain's Got Talent judge is said to have purchased an "outstanding" four-bedroom gated property in the village of Lisvane near Cardiff.
The "secluded" and "sought-after" residence is within close reach of Roberts's home town of Glynneath, the Mail On Sunday adds.
"Mr Hasselhoff has picked a great spot to look for an exclusive property," local estate agent David Ricketts commented. "I've lived there for 40 years and brought up three kids - he would have no problem doing the same with his Welsh young lady."
The 59-year-old Baywatch star has been dating factory worker Roberts, 31, since Britain's Got Talent held auditions in Cardiff back in January.
Hasselhoff has previously admitted that he "can't understand" Roberts's thick Welsh accent.
> David Hasselhoff misses 'BGT' premiere for girl