What 24 Celebrities Wore To Other People's Weddings

Because no one wants to tell Mariah Carey she can't wear white at their wedding. Photo: Rex Features

Having a royal attend your wedding is basically a sure-fire way to make sure everyone else on your list is RSVP'ing "Yes. Photo: Rex Features

Still the same Keith Richards but with a suit on. Photo: Rex Features

At the wedding of his friend Barbara Becker. Photo: Rex Features

Whoever said you can't wear gothic black to a wedding? Photo: Rex Features

Madonna looked very Cruella deVille at this New York Public Library wedding. Photo: Rex Features

Spotted heading to Alec Baldwin's wedding. Photo: Rex Features

At the wedding of Howard Stern and Beth Ostrosky. Photo: Rex Features

Casual wedding attire at the wedding of La La and Carmelo Anthony. Photo: Rex Features

Looking like actual royalty at the royal wedding of Prince Albert II of Monaco. Photo: Rex Features

So very chic. Photo: Rex Features

When in doubt, the most glamorous cover-up is a full-on fur coat. Photo: Rex Features

Attending George and Amal Clooney's wedding. Photo: Rex Features

Subtlety is overrated. Photo: Rex Features

In crimson velvet at the wedding of Katie Holmes and Tom Cruise. Photo: Rex Features

In a glam feathery shrug and her signature shades at George and Amal Clooney's wedding. Photo: Rex Features

Lady Gaga in a very atypical Grecian bridesmaid dress. Photo: Rex Features

A look that almost (almost) threatened to upstage Solange's all-white wedding. Photo: Rex Features

Ever the dapper gent and lady at the wedding of Prince William and Kate Middleton.

When you're attending the black-tie wedding of Amal and George Clooney, one does not show up in an average frock. Photo: Rex Features

The reality star did her best to upstage the bride in this revealing black dress. Photo: Rex Features

Elle Macpherson wore paparazzi-repellent shades at her arrival at a Miami wedding. Photo: Rex Features

Definitely what we would wear to a wedding if we had Chanel on speed-dial. Photo: Rex Features

We would expect no less from John Galliano attending a wedding. Photo: Rex Features

It's always risky inviting a high-profile celebrity to your wedding (even if you're one yourself), when there's the chance your big day will be overshadowed by their presence. But when it does happen, it's usually the best kind of spectacle. Ahead, 30 celebrity wedding guests trying their best to be low-key or the opposite — being extra fabulous — because they can't help it.