Despite plunging temperatures in the capital, the stunning actress hit the red carpet in a strapless sky blue Burberry dress in Leicester Square, watched on by hundreds of screaming fans.
She was joined by her co-star Owen Wilson and the pair put on a platonic display of affection as they huddled together and posed for photographs, perhaps in a bid to keep warm.
Jennifer Aniston braved plunging temperatures and wore a blue Burberry dress at the premiere of her new film Marley & Me in London last nightEventually the former Friends star put on a black jacket, clearly having had enough of the cold British weather, as hundreds of autograph hunters shouted and whistled.
She teamed her look with a gold chain while Owen cut a dash in a black suit and trainers.
During the filming of the movie, the pair were rumoured to be dating, but it turns out they are just very close friends.
She was joined by her co-star Owen Wilson, who cut a dash in a black suit
The actress eventually put on a black jacket to keep warm
Jen rugged up even more as she attended a Shoreditch House afterparty later in the evening
Other attendees at the premiere included a heavily pregnant Jools Oliver, who glowed in a floaty black dress and tuxedo jacket, and Dancing On Ice stars Roxanne Pallett and Zoe Salmon.
Skins actress Kaya Scodelario also turned out to see the film and teamed a red dress with black tights for an eye-catching look.
Soon after the premiere ended, Jennifer and Owen headed to the members club Shoreditch House where she was spotted letting her hair down - by playing a game of pool.
An insider said: 'As she came in you could tell she was in the mood for a bit of fun. She got talking to a fellow reveller and invited him to join her for a game of pool with her pals.
'She is probably the last person you would expect to play a game like that but she was so easy going with everyone, she wasn't fazed by a few stares.'
Jennifer and Owen were joined by comedian Steve Coogan and stayed until the early hours before heading back to their hotel.
Pregnant Jools Oliver glowed in a floaty black dress while former Emmerdale actress Roxanne Pallett looked great in a layered silver and white number
Dancing On Ice star Zoe Salmon donned a flattering cleavage-revealing blue gown
Skins actress Kaya Scodelario and Linda Lusardi injected some glamourMarley & Me tells the story of newlyweds John (Wilson) and Jenny Grogan (Aniston) who abandon the harsh winters of Michigan and head south to begin new lives in West Palm Beach, Florida.
They obtain jobs as journalists at local newspapers and buy their first home as they start a new life together.
In a bid to postpone starting a family John gets his wife a puppy named Marley for her birthday which turns into 'the world's worst dog'.
Speaking on the red carpet, Jennifer put the success of the film down to 'the simplicity of it and the realness'.
'The characters that are portrayed are beautiful,' she said.
Asked about any canine misbehaviour on set Owen said: 'There was one scene where he kind of lifted his leg and he wasn't supposed to.'
- Marley & Me will be released nationwide in cinemas on March 11
Danielle Lloyd looked ready to pop out of her outfit while former I'm A Celebrity contestant Gemma Atkinson went for a more demure look
Britain's Got Talent Winner George Sampson showed off his fancy moves