The Hollywood star however seemed to get away with donning what could have passed for a wedding dress when she attended the nuptials of her pals, businessman Oliver Luckett and his partner, chef Scott Guinn in Iceland.
"What a beautiful day with beautiful people" the Mean Girls actress Tweeted from the Borealis Hotel in Úlfljótsvan.
In a video which she shared on Instagram, the 30-year-old beamed with joy as she mingled with excited guests before the ceremony.
Nobody appeared to bat an eyelid at the radiant star's choice of attire - with no bride to 'compete' with, she might just have got away with the traditional faux-pas!
Looking fresh faced, the star wore her signature layered red hair long and loose, with simple make-up and a dainty white silk dress which featured a vintage-style neck tie and short ruffle sleeves. She covered up with an oversized long denim coat after the ceremony and carried a baby blue handbag.
The happy couple Luckett, 42, and Guinn, 28, met in Memphis, Tennessee and have been dating for nine years.
Their wedding was reported to have been attended by up to 400 guests, among them Iceland’s Prime Minister Bjarni Benediktsson, President Gudni Th. Jóhannesson, the Mayor of Reykjavik City Dagur Eggertson, and a host of high profile musicians, according to People.
Lindsay had even more to celebrate as she announced will be making a return to TV screens in Sky 1 comedy Sick Note starring Rupert Grint and Nick Frost, currently being filmed in the UK.
She shared a snap of her and her colleagues on Instagram last week writing “Back on set of my new TV show #SickNote.”
Lilo also seemed to be on form when she shared a behind-the-scenes video in a social media post which praised her cast mates.
"Best cast mates and crew!!" she posted, "So grateful to be with such talented, strong and honest people in the #UK #blessed"