Kaija Vahtra (née Udras, born 4 December 1986) is an Estonian cross-country skier who has competed since 2005.

At the 2010 Winter Olympics in Vancouver, she finished 16th in the team sprint, 31st in the individual sprint, and did not finish the 7.5 km + 7.5 km double pursuit events.

Vahtra competed at the FIS Nordic World Ski Championships 2009 in Liberec, finishing 11th in the team sprint, 15th in the 4 × 5 km relay, 21st in the individual sprint, and 54th in the 10 km event.

All results are sourced from the International Ski Federation (FIS).

This biographical article relating to Estonian cross-country skiing is a stub.