Blue tansy essential oil (Tanacetum annuum) is an aromatic oil obtained from the flowering tops of a plant associated with the Asteraceae family and Morocco and the Mediterranean region. It is known for its sweet, herbaceous, slightly fruity, and softly camphoraceous with a rich blue-floral character. and is used in perfumery, diffuser blends, and other traditional aromatic preparations.

Blue tansy essential oil is especially valued in high-end aromatherapy and skincare blends for its distinctive blue color and sweet herbal aroma. It is commonly used in calming diffuser formulas and gentle facial oils at very low dilutions.

This oil is especially appreciated for its german chamomile-style blending potential and is usually used in small amounts because its scent profile can strongly shape the finished aroma.