Australia's batting spearhead Steve Smith ended the 2019 Ashes Series as the highest run getter, amassing a whopping 774 runs against England over the course of the 5-match Test series.
"Steve has come...and with his technique that he's naturally developed, he's just confusing bowlers left, right and centre," the ICC website quoted Steyn as saying.
"I think he's a marvellous player. He's wonderful, he's got a great eye and a very difficult and weird technique to work out, which is working for him beautifully," he added.
Steyn also backed David Warner who, unlike Smith, didn't have a great run in the five-Test series in England.
"He's one of the best batters I've ever bowled to," Steyn said. "He puts you under pressure from ball one on day one of a Test match. You have to take what he can give you with what can happen. In this case, he's been found wanting around the wicket against someone like Broady (Broad) attacking that off stump. Sometimes that can happen. But he'll get to Australia, he'll find some form, he'll be playing around his mates and around his home crowd and that can quickly change for him.
"World-class players don't become rubbish overnight, especially over one tour. He'll be fine. I wouldn't drop him at all. I'd leave it as it is," he added.
Steyn, who retired from Test cricket in August, recently signed with Melbourne Stars for this year's Big Bash League. He will be playing six matches in what will be his debut season in the Australian T20 league.