Actor Julian Fellowes was also among the first guests to arrive, as was David Emanuel, who designed Princess Diana’s wedding dress - he wore a dark suit over a white T-shirt.
The comedian Jimmy Carr and his wife Karoline Copping were also in attendance.
Prince Harry’s former girlfriend Chelsy Davy arrived with Lady Melissa Percy, the Northumberland heiress.
Chelsy wore dark blue for the occasion and clung on to her hat - which featured a large blue flower.
Chelsy wasn't the only one who arrived holding their hats in the windy conditions, and staff were seen replacing a fallen potted tree which was knocked over onto the West Steps of the venue.
Hollywood actress Demi Moore arrived wearing a burgundy dress and matching fascinator.
She was preceded by supermodel Naomi Campbell.
Lord of the Rings and Armageddon actress Liv Tyler was also in attendance. The star wore a dark navy suit with a bow in her hair.
Property developer Nick Candy and wife Holly Candy, the singer formerly known as Holly Valance, also arrived.
Robbie Williams got a cheer from the crowds when he arrived in a limousine and waved back.
Meanwhile, singers James Blunt and Ellie Goulding arrived at the wedding in the same coach.
Eugenie will travel to St George’s Chapel in a 1977 Rolls Royce Phantom VI, accompanied by her father, the Duke of York.
The Rolls Royce was presented to the Queen in 1978 for her Silver Jubilee by the Society of Motor Manufacturers and Traders.
The Duchess of Cambridge, as Kate Middleton, travelled to Westminster Abbey in the same car on her way to marry the Duke of Cambridge in April 2011.
Former Take That singer Williams was with his wife and fellow X Factor judge Ayda Field. Their six-year-old daughter Theodora is one of the bridesmaids.
You’re Beautiful singer Blunt was accompanied by his wife Sofia Wellesley.
Livin’ La Vida Loca singer Ricky Martin was also there.
A heavily pregnant Pippa Middleton arrived with her husband James Matthews, wearing a deep green gown.
Meanwhile Meghan Markle - the Duchess of Sussex arrived via a side entrance wearing a coat.
A-listers attending the nuptials include David and Victoria Beckham, George and Amal Clooney, Sir Elton John and Ellie Goulding.
British fashion and portrait photographer Alex Bramall was named as the official photographer by Buckingham Palace on Friday morning.
“It is an honour and a privilege to be invited to photograph Princess Eugenie and Jack on this most special of days,” Mr Bramall said.
“I look forward with great excitement to capturing this significant occasion and wish them both a happy future together.”
7 News is airing every moment of Princess Eugenie's wedding live, as the only Australian broadcaster with cameras inside the Chapel. More info here!