Downes played in four of those five October victories, scoring tries in the wins over Swansea and Newport.
Principality Premiership head coaches, WRU and Regional academy staff, and selected journalists select the winner who receives £100 from the Principality Building Society, title sponsors of the competition.
Pontypridd head coach Paul John said: "Rhys has played exceptionally well so far this season. He came back from the Junior World Championship in Japan with good reports from coach Phil Davies and he's been training full time with the Blues ever since.
"As a result, his performances week-in, week-out have been consistently high, he's a threat to opposition, he's quick, he's got a great attitude and thoroughly deserves this award. It will be great if he can push on and get some regional rugby this season."
Downes, whose father and uncle also played for Pontypridd, added: "It's great to be recognised in this way, it's definitely down to the way we've been playing this season. The forwards are playing well giving the backs good ball to work with.
"There's a lot to play for this season and we want to be pushing for honours in all three competitions.
"On a personal note, I think my game has benefitted from staying injury free and from regularly training with experienced internationals at the Blues - that's definitely rubbed off on my performances with Ponty.
"My aims for this season are to continue performing well and get into the Wales Under 20 squad for the Six Nations. It would also be fantastic to get some Regional game time."
John is happy with his side's good start to the Premiership campaign, but is conscious of the task ahead.
"The boys have really worked hard since the start of the season, it's been great working with Dale McIntosh who demands high standards all the time and team manager Richard Langmead.
"The players are fully committed, and we have a stronger squad with youngsters creating competition for places in the starting line-up.
"It's good to be where we are at the moment, we have shown some consistency away from home that was lacking last season, winning in Bedwas and Ebbw Vale, where we didn't win last year, but we have some difficult games coming up. We have Aberavon, Cardiff, and the games against Llanelli and Neath now need to be re-arranged due to postponements. It's now a matter of performing well against the sides around us in the table."
Pontypridd host Cardiff on Friday night, this time in the inaugural British and Irish Cup.
"It's going to be a step up in standard to play against fully professional sides like Doncaster but it's a competition the whole town is looking forward to. A lot of Ponty fans are off to Ayr in February to support us, that's something we haven't had since our days in the European Cup. First up it's Cardiff, obviously a side we are familiar with but I'm sure the atmosphere at Sardis Road will be electric."
Rhys Downes factfile:
Place of Birth: Pontypridd
Club: Pontypridd / Blues academy
Position: Scrum half
Player most admired: Joost van der Westhuizen
Sportsman most admired: Cristiano Ronaldo
Biggest impact on career: My father Robert and the rest of my family
Career outside rugby: planning on taking electrician course in near future
Other sports played: Football, athletics