Dianella is a genus of about forty species of flowering plants in the monocot family Asphodelaceae and are commonly known as flax lilies. Plants in this genus are tufted herbs with more or less linear leaves and bisexual flowers with three sepals more or less similar to three petals and a superior ovary, the fruit a berry. They occur in Africa, South-east Asia, the Pacific Islands, New Zealand and Australia.
Several species of this genus, or the whole genus, are sometimes referred to by the common name blue flax lily, particularly in Australia.