Antonina Milyukova (1849-1917) was the wife (and after 1893, the widow) of Russian composer Peter Ilyich Tchaikovsky.

Milyukova briefly attended the Moscow Conservatory before being forced to abandon her studies, probably as the result of financial troubles. In 1877, she appears to have fallen in love with Tchaikovsky, not realising that he was homosexual. Tchaikovsky seems to have agreed to a marriage, that same year, in order to please his father and described Milyukova as ... a woman with whom I am not the least in love.

The marriage was disastrous, with separation following after only nine weeks. The couple never met again, but they remained legally married until Tchaikovsky's death. Tchaikovsky insisted that no blame attached to Milyukova though he came to detest her and to describe her as the reptile. She outlived Tchaikovsky by 24 years, but spent the last 20 years of her life in an insane asylum.

She was portrayed by actress Glenda Jackson in the film The Music Lovers.