Gemma has been counting down to this day all week, so we bet she's thrilled that her big day has finally arrived!
The fashion designer and bubbly reality star couldn't take the smile off her face as she walked down London's Oxford Street to preview her range in Evans' flagship store in Marble Arch.
Wearing a black patterned dress and white underlay with a black lace shawl, Gemma flashed a smile as she posed alongside some of her designs in the store.
Gemma tweeted today: "The biggest day of my life is here ha apart from my wedding it's a dream come true, off to @evansclothing #GCforEVANS."
She later added: "Today is the best day of the year for me."
Her co-stars also sent their congratulations. Best friend Bobby Norris said: "@missgemcollins so proud of you, congratulations babe." Meanwhile, Chloe Sims tweeted: "@missgemcollins well done GC you go girl."
Gemma's collection at Evans boasts "fun and fabulous pieces from bodycon dresses to pretty tops and the perfect kimono".
Gemma's range is available in sizes 16 to 24, with selected styles in size 26.
It was confirmed last month that Gemma was to become the new face of the plus size clothing store. Gemma reportedly inked a £50,000 deal with Sir Philip Green to "bring sexy back" to Evans.
She said at the time: "Today is one amazing day I am buzzing so happy over the moon woo hoo Evans @GemCCollection, it's a dream come true."
As Gemma celebrated her fashion success today, her co-star Charlie Sims announced his decision to quit TOWIE.
Charlie took to Twitter this afternoon in a series of messages to confirm his departure from the show, while also hinting at a split from girlfriend Ferne McCann.
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All you need to know about Gemma Collins: