Ruth Ellina Aitken, ONZM (née Fathers; born 31 July 1956 in Paeroa, New Zealand) is a New Zealand former international-level netball player and former head coach of the New Zealand national netball team, the Silver Ferns. A former goal-attack, Aitken represented New Zealand in the 1979 World Netball Championships in Trinidad and Tobago, playing two warm-up games and then in one match against Ireland.
Aitken became coach of the Silver Ferns in 2001, replacing Yvonne Willering. During Aitken's tenure as national head coach, the Silver Ferns won the 2003 World Netball Championships and the 2006 and 2010 Commonwealth Games, but came second to Australia at both the 2002 Commonwealth Games and the 2007 World Netball Championships. In February 2008, Aitken was re-signed as national head coach for a further four years.
In 2011, Aitken was named in the Queen's Birthday Honours List as an Officer in the New Zealand Order of Merit, alongside Silver Ferns captain Casey Williams. In late 2011, she retired as coach of the national team - and was later replaced by assistant Waimarama Taumaunu.
In Dec 2012, it was announced that Aitken would take over as Technical Director and National Coach of Netball Singapore.