Isabel Clark (1885 – 23 October 1915) was a New Zealand nurse who served in the First World War and died when the SS Marquette was torpedoed and sunk in 1915.

Her parents were Scottish settlers and the family lived at Ardgowan, near Oamaru, in the South Island of New Zealand.

Survivors reported that Clark and fellow nurse Marion Brown comforted each other on the deck of the ship before holding hands and leaping into the sea together.

[2] A commemorative plaque to Clark, and fellow Marquette casualties Mary Gorman and Catherine Fox, was placed in Waimate Hospital.

[6] Clark is named on the Mikra British Cemetery in Greece and in the Nurses' Memorial Chapel at Christchurch Hospital.