Niall Flannery (born 26 April 1991) is an English hurdler.
Flannery set his personal best in the 400 metres hurdles with a time of 48.80 seconds in Ostrava during 2014. He represented England at the 2014 Commonwealth Games in Glasgow.
He then competed in the 400 metres hurdles event at the 2015 World Championships in Beijing reaching the semifinals.
Flannery was twice British 400 metres hurdles champion after winning the British Athletics Championships in 2014 and 2015.