Hamilton is well on track for his sixth Drivers’ Championship this season and he has a 62-point gap at the top of the standings.
Mercedes team-mate Bottas is the closest challenger but his future is up in the air having entered the final months of his contract.
Rumours have circulated that Wolff is considering replacing the Finn with Esteban Ocon, who is without a drive this campaign.
But 1997 world title winner Villeneuve does not think it is fair the way the Silver Arrows are treating Bottas.
“Why would you do that?” Villeneuve said when asked about swapping Bottas for Ocon.
“Of course, Mercedes must continue with Bottas. How many times have they achieved P1 and P2 this season?
“Bottas is regularly faster than Hamilton, he scores his points.
“If he were to be half a second slower than Lewis in every race, like last year, then ok, you can replace him. But that’s not the case.
“[Ocon] hasn’t proven himself yet.
“I don’t know how good he is and I would never take that risk.”
Meanwhile, Bottas has recently admitted he is worried about the pressure of driving for his future.
“Some people might think that some drivers perform better under pressure when things are on the limit but for me it does not help,” Bottas said.
“That is the thing in this sport, balancing the risks just enough and pushing hard to try to take the opportunities but still not f*** up.
“When, contract-wise, you are on the limit it never helps.”
The F1 season returns from he summer break for the Belgian Grand Prix on September 1.