Soul singer John Legend has thrown his weight behind a female empowerment campaign by featuring a long line of ladies in his new music video.

The Grammy winner's promo for his latest single You and I (Nobody In the World) features a number of women staring into the camera through a one-way mirror.

Among those looking at their own reflection are celebrities including Legend's model wife Chrissy Teigen, transgender Orange is the New Black star Laverne Cox, and comedienne/cancer survivor Tig Notaro.

Also taking part in the emotional video is a topless pregnant woman cradling her baby bump, a young girl with Down's Syndrome, and an older woman who breaks down in tears as she shows the disfiguration left by a mastectomy.

The music video was made in conjunction with a campaign called #OperationGirl, which is being led by organisations focusing on empowering, educating and protecting the rights of women and girls.

A companion documentary called When I Look In The Mirror will also be released and features the women from Legend's video telling their own personal stories of heartbreak and triumph.

Legend supports the campaign's efforts in a statement which reads, "We live in a world where egregious injustices occur regularly against girls and women. We have a responsibility to take action and disrupt the conditions that allow for such tragedies to occur.

"Through #OperationGirl we hope to amplify the voices and impact of the many organizations doing great work on behalf of girls and women."