Stella Pennell (born 11 June 1965 as Stella-Maria van Hattum) represented New Zealand in Karate as Stella Lenihan from 1992 to 1996.
Pennell was Oceania Champion, New Zealand Champion, New South Wales (Australia) champion.
She was a repecharge finalist at World Karate Federation World Cup and World Championship.
Pennell retired from competition in 1996 and commenced coaching New Zealand Women's Team.
A recipient of Prime Minister's scholarship, she coached Krissie Paige to a silver medal at Junior World Championships in Greece 2001.Pennell retired from international coaching in 2006.
Pennell continues to teach karate at club level in Whitianga, New Zealand.
Pennell is the sister of former All White Frank van Hattum and Marie-Jose Griffith (prev.