The fashion brand has faced criticism on social media with people claiming they were confused over the decision.
Some questioned whether the brand had, in attempting to “appease a minority”, alienated cisgender female shoppers from purchasing the bras.
The advert featured Bappie Kortram, a bearded trans model from the Netherlands, who last year raised thousands of pounds online to remove his breasts.
The model was pictured kissing and fondling another model in the advert for the sports bra, which is sold for £28 in a “rainbow” of colours, in a nod to the Pride Flag.
It was advertised in a number of extra-large sizes, with “premium stretch fabric”, and a tagline that read “This is Love”.
The images provoked bafflement online, with one person commenting: “The bra/beard thing has me confused.
“If he’s trying to be more feminine, why keep the beard or is transwomen having beards a thing? Is he just gay and wearing a bra because he’s overweight and thinks it’s cute?”
Another said: “For the life of me, I cannot comprehend the fact that someone who does not have to wear a bra desperately desires to.”
One social media user said: “In their bid to appease a tiny minority, they’re alienating a huge majority.”
A post on Kortram’s GoFundMe page claimed his weight had stopped him from receiving surgery in the Netherlands and meant he was forced to go to Spain instead.
In a post from June 2022, he wrote: “Hello, the 18th I landed in Madrid, and the 20th my t--s got chopped off. We are now five days further from that beautiful moment and on Monday the 27th the bandage will come off.”
The post was accompanied by a selfie, apparently in a hospital bed after recovering from surgery.
Models.com, the fashion database, suggested that Kortram modelled for Calvin Klein in June 2022, although the precise date is unknown.
Kortram said in a statement: “I want to start with the fact that I still stand by my original message and the pride that I felt when Calvin Klein invited me to model for their Pride Collection of 2022.
“For me, it is important that trans men get to see diverse representation. Representation that shows more than thin muscular bodies, whose top surgery (removal of breast) are nearly perfect.
“There are trans men who don’t want the surgery, don’t have access to it or are flat-out denied. Their bodies count too and deserve to be seen in brands, products and commercials that validate their life.
“Even though I myself have gotten top surgery a month after the shoot, I still look back at this with pride and only focus on the people that felt validated and seen with this shoot.
“For those who replied with disgust, I would say only a person that loves themselves would be able to celebrate other forms of beauty.”
Calvin Klein was contacted for comment.