Four men and three women were hanged. They included a member of the ruling Al Sabah family and five foreigners.
Kuwait on Wednesday hanged seven people, including a member of the ruling Al Sabah family, state news agency KUNA said.
The royal was identified as Faisal Abdullah Al Jaber Al Sabah. He was sentenced to death in 2010 for killing his nephew, another prince, according to Kuwaiti newspapers. Observers said it appeared to be the first time a member of the Kuwaiti royal family was executed.
A Kuwaiti woman convicted of murder was also executed. She was found guilty of setting fire to a tent at her husband's wedding as he married a second wife and killing over 40 women and children.
Five foreigners were executed: three men and two women from Bangladesh, Egypt, Ethiopia and the Philippines who were convicted of offences that included murder, attempted murder, kidnapping and rape.
Wednesday's executions were the first in Kuwait since 2013 and come amid a rise in the use of the death penalty throughout the Gulf, according to human rights group Reprieve.
A few days ago, Bahrain, another Gulf kingdom, carried out its first executions since 2010.