Khovanshchina or The Khovansky Affair (Хованщина in Russian) is an opera by Modest Mussorgsky. The work was unfinished and unperformed at the composer's death in 1881, and was premiered five years later, after Nikolai Rimsky-Korsakov did the necessary work to complete the score. Because of the heavy cuts and "recomposition" at Rimsky-Korsakov's hand, Dmitri Shostakovich revised the opera based on Mussorgsky's vocal score, and this version of Khovanshchina is usually performed today. It received its premiere on 21 February 1886 in Saint Petersburg.

Like Mussorgsky's earlier Boris Godunov, Khovanshchina deals with an episode in Russian history, first brought to the composer's attention by his friend Vladimir Stasov. In this case, it concerns the rebellion of Prince Khovansky and his followers against Peter the Great, who was attempting to institute Westernizing reforms to the country. Ultimately, Peter succeeded, the rebellion was crushed and (in the opera, at least) his followers committed mass suicide.

While not as well known as Boris Gudonov, this opera is, in some ways, more accessible. The pace of the action is slow, but there is more in the way of traditional vocal lines as compared to the earlier opera's use of a more speech-like style. There are also some fiery set-pieces, in particular the Dance of the Persian Slaves. While Khovanshchina is not seen on stage often, especially in the West, it has been recorded several times.