A winter wonder! Katy Perry shimmers in plunging dress as she is honoured at Snowflake Ball... with Orlando Bloom by her side

She was the guest of honour at UNCIEF's 12th annual Snowflake Ball on Tuesday.

So Katy Perry ensured all eyes were on her as she walked the blue carpet at Cipriani Wall Street in New York City.

The 32-year-old, whose boyfriend Orlando Bloom was also at the bash, even looked like a delicate snowflake in her stunning sheer and shimmering silvery white gown.

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Guest of honour: Katy Perry ensured all eyes were on her as she walked the blue carpet at UNICEF's Snowflake Ball on Tuesday, held at Cipriani Wall Street in New York City

The Marchesa dress featured floral and lace detailing on the sleeves and plunging neckline, allowing Katy to showcase her ample cleavage.

Its pleated skirt was also see-through enough to give a glimpse of the pop star's underwear.

Katy teamed her gorgeous gown with a miniature clutch bag, several rings and flower earrings.  

The singer wore her raven locks slicked back and finished off her look with frosted eyeshadow, false lashes and raspberry lipstick. 

In awe! Katy was accompanied by handsome beau Orlando Bloom at the table

Cute couple: The two looked quite entertained by the onstage antics

Dressed the part: The 32-year-old even looked like a delicate snowflake in her stunning sheer and shimmering silvery white gown

Sheer delight: The Marchesa dress featured floral and lace detailing on the sleeves and plunging neckline, allowing Katy to showcase her ample cleavage, and a see-through skirt

Make them roar with delight in a pleated gown like Katy

As the guest of honor at the UNICEF snowflake ball, all eyes were on Katy Perry when she hit the blue carpet. And the Roar singer didn't disappoint as she looked stunning in a diaphanous dress by Marchesa.

Pulled from the Spring 2017 collection, the Grecian style gown featured delicate floral appliques, lace detailing and a full pleated skirt.

Katie teamed it with an acrylic box clutch by Edie Parker and a pair of efflorescent earrings and she wore her hair swept back to keep the focus on that sparkling iridescent confection.

Shop Marchesa's latest styles at Neiman Marcus by clicking right, then head down to the alternative gallery where we've gathered options from JS Collections, Liquorish, Maria Lucia Hohan and Alice + Oliva.

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Ready for her close-up: Katy teamed her gorgeous gown with a miniature clutch bag, several rings and flower earrings and dramatic make-up, while her dark locks were slicked back

Katy was being presented with the Audrey Hepburn Humanitarian Award during the evening. 

The Roar hit-maker's other half Orlando, 39, meanwhile looked suave in a classic tuxedo with bow tie and white shirt.

Katy and Orlando were rumoured to have split last week, but showed they were still going strong on Thanksgiving.

By her side: Orlando was there to support his girlfriend as she was honoured with the Audrey Hepburn Humanitarian Award

Dapper: The 39-year-old Lord Of The Rings star looked suave in a classic tuxedo with bow tie and white shirt

She wouldn't miss it: Katy was also supported by her best friend Allison Williams

The Lord Of The Rings star spent the holiday with Katy and her family, with all the family sporting matching pyjamas.

Katy was also supported on Tuesday by her best friend Allison Williams, who showcased her classic style in a one-shouldered black gown. 

The 28-year-old Girls star kept her accessories to a minimum, aside from a pair of dazzling drop earrings, and wore her brunette locks in an elegant updo.

Classic beauty: The 28-year-old wore a one-shouldered black gown and dazzling drop earrings, keeping her other accessories to a minimum 

Finishing touches: Allison wore her locks in an elegant updo and added dark eye make-up

Cheeky! Allison couldn't resist pulling some funny facial expressions on the blue carpet 

A flare for the dramatic: Brooke Burke Charvet picked a theatrical strapless gown with a daring slit up the front to showcase her slender legs

Allison added dark eye make-up and pale pink lipstick.

Brooke Burke Charvet was another beauty in black, picking a dramatic strapless gown with a daring slit up the front to showcase her slender legs. 

The 45-year-old was joined at the black tie affair by her husband David Charvet.

One good-looking couple: The 45-year-old was joined at the black tie affair by her husband David Charvet

Ladies in red: Patina Miller (L) and Maggie Q both sizzled in floor-length scarlet gowns

Simple but chic: Octavia Spencer bucked the trend of wearing dresses and picked a pantsuit

Blondes having fun: Stephanie March (L) and Tea Leoni looked stylish in black dresses

Party people: Patina Miller and Tea Leoni posed with Erich Bergen and Tim Daly

Lippy ladies: Mia Moretti wowed in a nude and black gown with a fur trim whilst Caitlin Moe dazzled in a floor length glittering black gown whilst they both donned a glossy red lip 

Meanwhile Octavia Spencer was clad in a simple but chic black pantsuit, and Tea Leoni picked a strapless black gown.

Maggie Q wasn't one of the stars shunning bold colours, instead opting for an eye-catching red satin creation.

Guests at the bash, which raised money for UNICEF, were treated to cocktails and dinner, as well as a performance from Sara Bareilles. 

Legs eleven! Brooke flashed her tanned and toned pins as she struggled to adjust her gown 

Coming through: Whilst she may have looked glamorous on the blue carpet, she seemed to have some trouble with the practical natures - such as walking - in the gown 

Four of a kind: Once inside Brooke posed with Anderson, Dr. Jennifer Ashton and Octavia

Three's company: Cindi Jaliher, Katy Perry  and Carol Edwards cuddled up for snaps 

Wowing in white: Katy stood out in her bright gown alongside Sara Bareilles and Caryl Stern

Brunette beauties: Mia Moretti grabbed Katy Perry for a sweet snap of the pair 

Glittering gowns: UNICEF NextGen Chairs Sterling McDavid and Daria Daniel stood out 

Monochrome magic: Gala Co-Chair Gillian Miniter and Philanthropist Hilary Gumbel complemented each other in their black and white gowns 

Music maestro: The Doo Wop Project set to work entertaining the crowds 

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