Howells joins fellow 18-year-olds Calum Davies, Jordan Collier and Joe Davies in being made available to Neath by Steve Tandy.
After making his Wales debut on the two-Test tour of Japan last month, Howells completed a remarkable season in which he also played college, age grade and regional age grade rugby. He also captained Wales Under 18 and played for Wales Sevens before graduating to the senior side.
But as part of his continued development, Howells will wear the famous Neath black throughout 2013-14 as the Ospreys have agreed to give him much-needed experience in the Welsh Premiership.
The availability of Howells, as well as the three other junior Ospreys, is something which is a big boost to new Neath coach Neil Edwards.
He said: “We’re delighted our solid links with the Ospreys are continuing into 2013-14. Our quartet of Ospreys players are up and coming stars and we’re delighted they’re going to be turning out for Neath.
“I know they can all do a good job and Dafydd has already proved that at the highest level after winning full international caps for Wales this summer.
“All four are still developing as players of course and playing in the Premiership, coupled with their continued progress at regional level, can only help them, the Ospreys and Neath.”
Howells, Calum Davies and Collier all made appearances for Neath last season with the trio coming through the Ospreys’ Academy system. Joe Davies on the other hand, is new to The Gnoll.
While Howells is a name more well known to Wales fans, the other three acquisitions should benefit Edwards enormously.
Calum Davies is a back-row forward. He turned out three times for Neath and the back end of last season.
Previously with Tonmawr, Collier played seven times for Neath in the last campaign while Joe Davies will make his first senior rugby appearance when he turns out for Neath in 2013-14. In his first year with the Ospreys last season, he played for their Under 18 Academy side in regional rugby.
