Robinson, who scored a try on his senior Wales debut against the Barbarians last June, is one of three changes to the side that beat Italy a fortnight ago, with Dragons No 8 Ieuan Jones also making his first start of the Under 20 Six Nations and Steffan Hughes returning to the centre with Thomas Pascoe ruled out through illness.
In a positional change, captain Ellis Jenkins switches to the blindside with flanker Sion Bennett sitting out the game through injury. Dragons duo Hallam Amos and Jack Dixon take up places on the bench while Blues outside half Rhys Patchell is also unavailable for the Scotland trip through injury.
Wales Under 20 head coach Danny Wilson said, "Ashley Evans has been playing well on the wing, but it's a case of preparing for the Junior World Championship and tweaking the side to give players opportunities as we have done throughout this tournament. It's not a case of regional players walking straight into the side but, at the same time, it's great to create competition within the squad."
Wales travel to Inverness on the back of three wins from their three games so far in the Under 20 Six Nations but Wilson and captain Jenkins are not underestimating the challenge ahead.
Wilson said, "This Scotland side is the best Scottish age grade side I've seen in a good few years. They've beaten Italy and Ireland and ran England close so we are going to have to be at the top of our game to come away with a result. The set piece is key, as it has been throughout our Six Nations campaign, and hopefully the weather will be an improvement on the conditions in Italy and allow us to play some attacking rugby."
Skipper Jenkins insists there is no talk of a Grand Slam amongst the players.
"Scotland are a very tough side and we have trained well this week to prepare, as a group and with the senior side. We have also done a lot of work on Scotland so Friday's challenge is the only thing on our minds. We are not thinking about the England game."
Wales Under 20 team v Scotland (Caledonian FC, Inverness, Friday 8 March, 7.35pm)
Jordan Williams (Scarlets/ Llanelli); Harry Robinson (Blues), Cory Allen (Blues / Cardiff), Steffan Hughes (Scarlets / Llanelli), Aaron Warren (Llandovery); Sam Davies (Ospreys / Swansea), Rhodri Williams (Scarlets/ Llandovery); Gareth Thomas (Scarlets / Carmarthen), Ethan Lewis (Blues / Cardiff), Nicky Thomas (Ospreys / Swansea), Carwyn Jones (Scarlets/ Carmarthen), Rhodri Hughes (Ospreys/ Swansea), Ellis Jenkins (capt, Blues / Cardiff), Daniel Thomas (Scarlets / Llanelli), Ieuan Jones (Dragons)
Replacements: Elliot Dee (Bedwas), Nicky Smith (Ospreys / Swansea), Dan Suter (Ospreys / Bridgend), Jack Jones (Ospreys / Rovigo), James Benjamin (Bedwas), Joshua Davies (Dragons / Bedwas), Jack Dixon (Dragons), Hallam Amos (Dragons)