Nina Kathy Rillstone (born April 15, 1975, in Brentwood, Essex) is a New Zealand long-distance and marathon runner.

Rillstone set a national record for the marathon at the 2007 IAAF World Championships in Osaka, Japan, with a time of 2:33:58, finishing in thirteenth place.

[2] Rillstone represented New Zealand for the 2008 Summer Olympics in Beijing, and competed in the women's marathon.

She ran and finished the race in sixteenth place, with a best possible time of 2:31:16, nearly two minutes short of her personal best set in Nagano.

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