Wearing her brunette hair in loose waves, Meghan also recycled a camel-coloured trench coat by Martin Grant and accessorised her chic look with black stilettos.
"That Dion Lee dress on her is a triumph," fashion expert Donny Galella told New Idea.
"Modern, edgy yet classy. So chic! The matching navy shoe, just adds more brilliance to this spectacular look. My favourite look so far on this tour."
"Love the navy pumps matched with the navy dress, so chic," Donny added.
"Serious fashion points awarded for choosing Dion Lee, one of Australia’s top designers.
"Also nice to see her recycle the Martin Grant trench coat which she wore the other day."
Dion Lee is a New York-based fashion designer who grew up in Cronulla.
He established his popular brand at the age of 23.
Lee debuted at Australian Fashion Week in 2009 after graduating from Sydney Institute of Technology the year prior.
He was the first designer to stage a runway presentation at the Sydney Opera House in 2010
Just three days ago, Dion Lee unveiled the new uniforms of staff at Sydney Opera House - where he called the navy tailored jacket he designed for front-of-house staff as his "hero piece".
"I approached the uniforms the way [Uzon the designer of the Opera House] approached design," Lee said, the Sydney Morning Herald reported.
"The way it folds over in a three dimensional way and the way Utzon designed the building with a podium so that visitors rise above - I tried to do the same thing with the uniforms."
Harry and Meghan were given a rapturous reception as they arrived in Melbourne.
Crowds screamed for the duke and duchess as they greeted well-wishers and were handed toys and flowers.
Members of the crowd also started singing Stand By Me, which was performed at Harry and Meghan’s wedding in May.
Harry and Meghan – who arrived 20 minutes late to meet wellwishers – abandoned their strict scheduling as they met the crowds.
The duke and duchess stopped to play with five-and-a-half-month-old Harriet Bonaddido and chatted with her mother Jessica.
The 28-year-old said: “As soon as I introduced my daughter to Harry he said ‘that’s a great name’.
“Maybe they will choose it for their own child which would be fun.
“Meghan was right behind him and was playfully tickling her toes and said how sweet it was that I’d brought her out today.”
The couple then met the Governor of Victoria at Government House, where they met community leaders and watched sporting demonstrations with ambassadors from the This Girl Can campaign.
In the afternoon, the couple will take a tram ride to the coast where they will meet primary school children and take part in a beach clean.