Sinead Jack Kısal (born 8 November 1993 in Mount Hope, Trinidad) is a Trinidad and Tobago female professional volleyball player of the Trinidad and Tobago women's national volleyball team.

She participated at the 2011 Women's Pan-American Volleyball Cup.

Jack won the 2013 NORCECA Championship Best Middle Blocker award.

For the 2016–2017 season she signed with the Turkish club Galatasaray Istanbul.

This biographical article relating to volleyball in Trinidad and Tobago is a stub.