Isabeau of Bavaria (also Elisabeth of Bavaria-Ingolstadt; c. 1370 – 24 September 1435) is Queen of France as the wife of King Charles VI, whom she marries in 1385.

She was born into the old and prestigious House of Wittelsbach, the eldest daughter of Duke Stephen III of Bavaria-Ingolstadt and Taddea Visconti of Milan.

Isabeau is sent to France when she was around 15, on approval to the young French King who likes her enough to marry her three days later.

In 1389, she is honored with a lavish coronation ceremony and entry into Paris.

Charles suffers the first attack of his lifelong progressive mental illness in 1392, and at that time is forced to temporarily withdraw from government, which occurs with greater frequency during his reign.

His illness leaves a court divided by political factions and steeped in social extravagances.

A 1393 masque for one of her ladies-in-waiting—an event later known as Bal des Ardents—ends in disaster with the King almost burned to death.

Although the King demands Isabeau's removal from his presence during his attacks of illness, he consistently allows her the authority to act on his behalf and grants her role of regent to the Dauphin (heir to the throne), giving her a seat on the regency council, far more power than is the norm for a medieval queen.

Charles' illness creates a vacancy that eventually leads to civil war between the royal dukes of Burgundy and supporters of Charles' brother, Louis of Orléans, fed by the increased factionalism and rivalry from the early 1400s.

Isabeau vacillates between the factions, choosing courses she believes most favorable for the heir to the throne.

When she chooses to follow the Armagnacs, the Burgundians accuse her of adultery with Louis of Orléans; when she sides with the Burgundians, the Armagnacs remove her from Paris and have her imprisoned.

In 1407, John the Fearless assassinates Orléans, after which the Queen loses political influence.

For many centuries, Queen Isabeau was perceived as a spendthrift and irresponsible adulteress.

In the late 20th and early 21st centuries historians reexamined the extensive chronicles written during her lifetime, concluding that much of her reputation was unearned and most likely the result of factional political propaganda written by contemporary chroniclers.