The Peruvian joins the League One club until January 2021, which will mark his first taste of senior football in England.
Since arriving from Deportivo Municipal in October 2020 for £210,000, the 22-year-old has spent the early stages of his Magpies career in the under-23s.
Vilca was due to go out on loan in January but an injury delayed his development.
The 22-year-old: “I’m really excited to come to Doncaster and have a chance to show what I can do in England.
“I feel since joining Newcastle I have improved a lot already so this is the next step for me.
“I have heard a lot of positive things about the club and the players here and I am looking forward to meeting my team mates.”
Doncaster, managed by Richie Wellens, are currently bottom of League One, collecting just one point from their opening five matches.
We’ve gathered the best of today’s Premier League speculation below…
1. Govou fumes over Cornet exit
Former Lyon and France star Sidney Govou has questioned the decision to let ‘warrior’ Maxwel Cornet move to Burnley. (Twitter) (Photo by FRANCK FIFE/POOL/AFP via Getty Images)
Photo: FRANCK FIFE
2. Albion keen on Nketiah
Brighton and Hove Albion were interested in Arsenal ace Eddie Nketiah this summer. (Sussex Live) (Photo by Justin Setterfield/Getty Images)
Photo: Justin Setterfield
3. Cherries snubbed in Greenwood approach
Swansea City and Bournemouth were among those to fall short in their pursuit of Leeds United youngster Sam Greenwood this week. (Football Insider) (Photo by George Wood/Getty Images)
Photo: George Wood
4. Baggies want Molumby
West Brom are already lining up to take the permanent option on the loan deal of Jayson Molumby next season. (Birmingham Live) (Photo by Srdjan Stevanovic/Getty Images)
Photo: Srdjan Stevanovic