A three-minute video emerged on Saturday of a man identified by Afghan officials as a Taliban member shooting the kneeling woman five times to cheers from a crowd of around 150 men in Parwan province.
The Foreign Secretary urged the authorities in Kabul to bring those responsible to justice amid international efforts to improve the status of women in the country.
"I am shocked and disgusted by reports that an Afghan woman has been publicly executed by the Taliban," he said.
"The UK Government condemns this action unreservedly and calls on the Afghan Government to identify the perpetrators and bring them to justice.
"Such deplorable actions underline the vital need for better protection of the rights of women and girls in Afghanistan, where they continue to face huge challenges.
"We are working closely with the Government of Afghanistan, local and international NGOs, civil society and international partners to improve the status of women and girls in Afghanistan, so they can participate as fully as possible in a future, peaceful Afghan state."