Ready for bed Cressida? Prince Harry’s ex looks a little bleary eyed as she swaps her sequined mini dress for pyjama pants after the Royal Academy party in London

She's been working hard on her flourishing career as an actress, but last night Cressida Bonas took the chance to let her hair down as a star-studded party in London. 

The Burberry muse, 27, who previously dated Prince Harry hit the Royal Academy of Arts Summer Exhibition Preview Party and was looking a little tired and bleary eyed by the time she left the star-studded bash. 

And she even slipped into something a little more comfortable for the journey home, swapping her sequined mini dress for a pair of floral pyjama pants and a black vest. 

Cressida Bonas posed up a storm with a female friend at the star-studded Royal Academy of Arts Summer Exhibition Preview Party 

Cressida looked a little weary as she chatted on her phone after the party 

The aspiring actress has clearly made the most of her night out and looked ready for bed as she chatted on the phone after climbing into her waiting car.

Earlier in the evening, Cressida had arrived sporting a high glamour look, choosing a heavily embellished dress featuring a bold floral print in burgundy, orange and silver for the occasion.

Her accessories were pure rock chick look as she opted for a pair of gold-studded clogs and a £2595 Burberry leather jacket with heavy duty zips.

The aspiring actress wore her blonde locks tumbling over her shoulders in tousled strands, and showed off her dewy, natural glow by keeping her make-up to a minimum.  

Cressida went for a high glamour look, choosing a heavily embellished dress featuring a bold floral print in burgundy, orange and silver for the occasion

Quick change: The actress swapped her mini dress for a pair of comfortable pyjama style pants and a black vest 

The aspiring actress wore her blonde locks tumbling over her shoulders in tousled strands

The Royal Academy of Arts Summer Exhibition took place at Burlington House in London.

Guests posed in the famous courtyard of the 19th century manor house, which is home to the Royal Academy itself.

The party was a private view of the world's oldest and largest open art competition and exhibition, featuring 1,000 works from 13,000 submissions.

Cressida also posed with model Clara Paget who went for a 90s boho vibe in a black crop top and floral skirt, with a thick choker

Partying up a storm: Cressida and her friend had clearly enjoyed their night on the town 

The Burberry muse has recently played the part of a series of iconic cinema heroines including Audrey Hepburn's Holly Golightly in a short film for the lifestyle website Semaine

And Cressida looked to be having a great time at the event as she mingled with stars such as Katherine Jenkins and Jessie Ware.

Getting into the party spirit, she slung an arm around a female companion as the pair showed off their brightest smiles for the cameras.

Her friend had opted for a very similar look in studded ankle boots, a mini dress and a leather jacket. 

Cressida added an edge to her pretty dress with a pair of studded fringed ankle boots

Cressida dated Prince Harry for two years before splitting in April 2014. It was rumoured that she couldn't face the pressures of life as a royal spouse and wanted to pursue her acting career

Cressida also  posed with model Clara Paget who went for a 90s boho vibe in a black crop top and floral skirt, with a thick choker. 

It's a busy time for Cressida who is working towards landing her first part as a leading lady on screen. 

She's recently played the part of a series of iconic cinema heroines including Audrey Hepburn's Holly Golightly and Ilsa Lund from Casablanca in a short film for the lifestyle website Semaine. 

The blonde aristocrat has shot shorts with fashion brands Burberry and Mulberry

Since her split from Prince Harry two years ago Cressida she has blossomed and regularly steps out looking polished and glamorous at fashion shows and society events

Cressida posed in the famous courtyard of the 19th century manor house, which is home to the Royal Academy itself

The 27-year-old model and RADA-trained thesp also recreates one of Gwyneth Paltrow's most famous parts as Margot in the Royal Tenenbaums in the two-minute 33-second flick.

Previously the blonde aristocrat has shot shorts with fashion brands Burberry and Mulberry, taken to the stage in one-woman play An Evening With Lucian Freud in London and had bit parts on TV and in film.

But, this marks her first lead speaking part in an art house movie. 

The rising star recently made headlines for her steamy scenes in a new American horror film, The Bye Bye Man, which included a moment where she appears to be naked in bed

Cressida played a potential bride-to-be in Julian Fellowes ITV adaptation of the 1858 Anthony Trollope novel Doctor Thorne

The trained dancer showed off her toned legs in a sequinned mini dress

Cressida recently made headlines for her steamy scenes in a new American horror film, The Bye Bye Man, which included a moment where she appears to be naked in bed.

Previously, she has been cast in more demure parts, like her recent turn as a potential bride-to-be in Julian Fellowes ITV adaptation of the 1858 Anthony Trollope novel Doctor Thorne.

Cressida dated Prince Harry for two years before splitting in April 2014. 

It was rumoured that she couldn't face the pressures of life as a royal spouse and wanted to pursue her acting career. 

The actress was clearly uncomfortable in the spotlight during her relationship with the royal and was often seen dressed down in scruffy dungarees with her hair pulled back in a scrunchie. 

But since the split two years ago she has blossomed and regularly steps out looking polished and glamorous at fashion shows and society events.