The Dutch forward, who arrived from Ajax for around £6million earlier this summer, scored a screamer on his first appearance in a Magpies shirt on Tuesday evening.
After striking a free kick against the Latics' wall, the new man slammed the rebound into the top corner to offers supporters a taster of what might be to come this season.
Jack Colback also enjoyed his first run-out in the 2-1 reverse after his controversial switch from Sunderland, and Pardew was full of praise for the pair.
Speaking to the Chronicle, the Newcastle boss said: “It was a nice bonus for us to see that quality on the pitch from one of our new players – it was a fantastic goal [from De Jong].
“Siem got a great goal and showed he is going to produce those moments [and] I thought Jack was terrific in midfield."
Newcastle have also added Remy Cabella to their ranks this summer, and the trio will be joined by Netherlands international Daryl Janmaat.
Pardew could also make another move for a striker in this window following the losses of Luuk de Jong, Loic Remy and Shola Ameobi at the end of last season.
Monaco's Emmanuel Riviere is likely to be the next arrival at St James' Park, and Sky Sports reported on Wednesday afternoon that the forward was close to sealing his move.
Meanwhile, Newcastle are hopeful that the signings of Dutch duo De Jong and Janmaat will be enough to persuade Tim Krul to remain on Tyneside this season.
The Netherlands goalkeeper has been linked with moves to the likes of AC Milan and Juventus in recent months, but the club are said to be confident of keeping their number one.