A-list actress, Kristin Scott Thomas, 57, wore a long monochrome Christian Dior number and wore a Time's Up badge in a bid to show her support.
And fellow actress Andrea Riseborough, 36, followed suit in a thigh-split number by Elie Saab to walk down the red carpet with Phyll Opoku-Gyimah, co-founder of UK Black Pride from 2005.
As well as being a trustee of gay rights group Stonewall, she was formerly head of political campaigns and equality at the Public and Commercial Services trade union.
According to Vogue, members of the Time's Up initiative sent around a letter urging guests 'to wear black to the awards ceremony, to follow suit from our sisters who attended the Golden Globes.'
Just a month ago, most of the stars who attended the Golden Globes wore black in a show of solidarity towards victims of sexual harassment.
Also joining the cause was former TOWIE star Lydia Bright, 28, who showed off her curves in a beautiful strapless fishtail gown by AloNuko which flattered her figure perfectly. She sported a golden glow after her recent trip to Cape Verde.
Meanwhile, Dermot O'Leary and wife Dee Koppang complemented one another perfectly in their matching ensembles.
They arrived shortly after Sian Welby, who was the first celebrity to walk the red carpet on the night.
The television presenter, 31, looked incredible as she dared to go underwear free under her semi-sheer panelled black dress.
She teamed the number with a studded pair of nude strappy heels, which gave a glimpse of her inked feet.
Presenter Edith Bowman, 44, looked resplendent in a brocade strapless number which was cinched in at the waist
The Shape of Water , directed by Guillermo del Toro, has been nominated for a total of 12 awards with Darkest Hour and Three Billboards Outside Ebbing, Missouri both receiving nine nominations. Blade Runner 2049 , Dunkirk, I, Tonya , Call Me by Your Name and Phantom Thread were also nominated for multiple awards.
And while the dress code was looser for the Grammys, stars walked the red carpet carrying white roses in support of gender equality.
This year's BAFTA Awards are being hosted by Joanna Lumley after Stephen Fry announced he was stepping down after hosting for 12 years, from 2001 to 2006 and again from 2012 to 2017. TV presenter Jonathan Ross presented during the intervening years.
She said at the time: 'Honestly how exciting is this? It's just so unbelievably thrilling. I always looked at the BAFTA Awards with Stephen Fry there forever more, so who thought I'd turn into Stephen Fry? I said yes indecently quickly. Thank you, thank you, I'll see you on the night.
And after stepping down from his coveted position, Stephen Fry said: 'Every one of the 12 BAFTA film award ceremonies that I had the privilege of hosting has a place in my memory.
'The mixture of glamour, glory, drama and - occasionally - embarrassment and hiccup holds a unique place in the British film calendar.
'Over the last two decades I have especially loved watching the emergence of new young film talent behind and in front of the camera. But after so long a time I felt it only right to stand down and let others take the Baftas on to new heights and greater glories.
'I want to thank all the production staff, Amanda Berry and her wonderful BAFTA colleagues, the BBC and all those who helped make every year so enjoyable.
'I reserve especial gratitude and imagination for Ivor Baddiel and Phil Kerr, whose work on the scripts was so skillful it made people think I'd written every line myself.
'What fun it will be to watch BAFTA 2018 without my heart hammering, mouth drying and knees trembling.'
The 2018 BAFTAs will be live on air on BBC One on Sunday. The star-studded ceremony is also being live-streamed on the BAFTAs official Facebook page.
The first BAFTA award ceremony took place in 1949 and presented the initial awards for films made in 1947 and 1948.
Following the nomination announcements back in January, BAFTA was criticised about the absence of women making this year’s Best Director shortlist.
Greta Gerwig, director of Lady Bird, was notably absent from the shortlist –despite the film receiving nominations for Original Screenplay, Leading Actress and Supporting Actress and winning two Golden Globes last week.
Angelina Jolie also failed to make the cut for directing First They Killed My Father, nominated for the category of Film Not in the English Language. Other female directors left off include Lucy Cohen, who directed Kingdom of Us, and Rungano Nyoni for I Am Not A Witch – despite both having made it into the Outstanding Debut by a British Writer, Director or Producer category.
Of all the 2018 BAFTA Film nominees in non-gender-specific categories, only around 20 per cent were women.
Kathryn Bigelow is the only woman in history to win the Best Director award – for The Hurt Locker in 2010.
BAFTA boss Amanda Berry told Saturday’s BBC Radio 4 Today programme: ‘Well, I have to admit there are no female directors in the director category, but there are five female directors nominated elsewhere’.
British movies such as Film Stars Don't Die In Liverpool and Paddington 2 have received more attention than at the big US ceremonies.
The EE Rising Star Award, voted for by the public, was a battle between Daniel Kaluuya, Florence Pugh, Josh O’Connor, Timothée Chalamet and Tessa Thompson. Get Out star Daniel emerged the winner.
© Associated Newspapers Ltd.