The esraj or esraaj (from the Punjabi: ਇਸਰਾਜ Shahmukhi: اسراج) is a stringed instrument found in two forms throughout South Asia.

In West Bengal, Rabindranath Tagore made this instrument mandatory for all the students of the Sangeet Bhavan (Music Academy) in Visva-Bharati University (otherwise known as Shantiniketan).

The dilruba and its variant, the esraj, have a similar yet distinct construction style, with each having a medium-sized sitar-like neck with 20 heavy metal frets.

There are two variants of esraj played in Shantiniketan; the traditional variety, and the modern model developed by Ranadhir Roy.

This version is longer, with a wider fingerboard, and with an additional, diminutive "jawari" bridge near the peghead for the three drone strings.

An instrument maker of Kolkata, named Dulal Patra worked to develop the newer model of esraj as per Roy's instructions.