Cynthia Nonyelum Sember ( Ofili; born 5 August 1994) is an American-born British track and field athlete, specialising in sprint hurdles. She finished fourth in the 100 metres hurdles final at the 2016 Olympic Games. Her best times, 12.60 secs for the 100 metres hurdles in 2015, and 7.89 secs for the 60 metres hurdles indoors in 2016, rank her third on the British all-time list for both events behind her sister and British record-holder, Tiffany Porter and Olympic champion heptathlete, Jessica Ennis-Hill.