Celebrities are turning up en masse for the Cannes Film Festival 2011. The star-fest received an extra boost when Lady Gaga appeared up for a surprise performance.

Gaga rolled into Cannes on Wednesday and looked her outrageous best in a black lace outfit with a red headscarf over her two-tone hair as she performed on the waterfront while the official Cannes Festival launched.

Lady Gaga put in a surprise performance at Cannes.
Lady Gaga turns up for an impromptu performance at Cannes.

[View:http://www.youtube.com/watch?v=ZAmDM9p7dGM]

Uma Thurman stunned the crowd in a white Versace gown, saying: “It’s sexy isn’t it! I had to have it made because you know how it is for us tall girls. It’s impossible to find anything in a store.”

Uma Thurman Cannes
Uma Thurman in a white Versace evening dress.

Thurman, 41, is on the judging panel this year, along with Jude Law and Robert De Niro.

Actress Melanie Laurent, Jury members Robert De Niro, Uma Thurman and Mahamat-Saleh Haroun onstage at the Opening Ceremony at the Palais des Festivals during the 64th Cannes Film Festival
Melanie Laurent with jury members Robert De Niro, Uma Thurman and
Mahamat-Saleh Haroun onstage at the Opening Ceremony at the Palais des
Festival.

The Cannes Film Festival 2011 kicked off with a gala ceremony and opening film, Woody Allen’s Midnight In Paris starring Owen Wilson, Rachel McAdams, Michael Sheen and Carla Bruni. Only Bruni did not attend.

British actor Michael Sheen, Canadian actress Rachel McAdams and US director Woody Allen pose on the red carpet before the opening ceremony and the screening of 'Midnight in Paris' at the Cannes Film Festival.
Michael Sheen, Rachel McAdams and Woody Allen on the red carpet before the opening ceremony and the screening of ‘Midnight in Paris’ at the Cannes Film Festival.

Other red carpet winners included Salma Hayek in a red ruffled Gucci dress.

Actress Salma Hayek attends the Opening Ceremony at the Palais des Festivals during the 64th Cannes Film Festival
Salma Hayek at the Cannes Palais des Festivals opening ceremony.

US actor Adrien Brody poses during the photocall of 'Midnight in Paris' presented out-of-competition
Adrien Brody poses during the photocall of Midnight in Paris.

Tilda Swinton at Cannes Film Festival.
Actress Tilda Swinton poses for the photographers at the Cannes Film Festival.