The mum-of-one chose a stunning black and silver Kolchagov Barba couture gown to walk the red carpet on Sunday 14 May.
Piper took to Instagram to share a sneak peek of her fashion choice with her thousands of followers before arriving at the Royal Festival Hall in London.
“Dinner is ready!,” Piper wrote.
The billowing black dress was covered in a beautiful silver metallic floral sheen - paired with strappy black heels from River Island.
Piper also shared a video on social media of herself riding to the venue.
“Here we come! Think I needed an extra car for my Kolchagov Barba gown,” she wrote.