"Amy is a style icon," Louis told the Herald. "She's our very own Jackie Kennedy."
Louis says Amy's (33) understated fashion choices make her stand out.
"She's always slightly understated but she's always very nicely turned out, very well-dressed, very chic."
Louis credits her dad Harold's influence.
"She understands fashion because her dad, Harold Huberman, was in the rag trade all those years ago and so was her mum."
Amy has talked about launching her own clothing line at some stage -- and Louis is now encouraging the Threesome actress to follow in the footsteps of her father.
"I think it makes sense because her father is a designer, and when you think about it Amy Huberman is a great name," he said.
"You can just see the label. I could see it taking off -- who knows, maybe she'll even go into men's clothes."
Louis is famous for dressing a host of showbiz, sport and political personalities ranging from Jedward at the Eurovision, to Westlife, Amy's hubbie Brian O'Driscoll and Bertie Ahern.
But if Amy is our very own version of former US first lady Jackie Onassis Kennedy, Louis says that our answer to JFK is ... Mark Cagney.
"I think Mark Cagney is one of the sharpest dressed men out there," the designer told the Herald. "To me he's the best-dressed man in Ireland."
This may come as a bit of a shock, given that Mark is best known for wearing novelty socks when presenting Ireland AM.
But Louis maintains that Mark knows exactly what he is doing. "He understands clothes and he knows how to wear them," Louis said.
"He's very knowledgeable about clothes and the cut and how they should fit. And he wears good socks."