Louis de Buade, Comte de Frontenac et de Palluau (French pronunciation: [lwi də bɥad kɔ̃t də fʁɔ̃tənak e də palɥo]; 22 May 1622 – 28 November 1698) was a French soldier, courtier, and Governor General of New France in North America from 1672 to 1682, and again from 1689 to his death in 1698. He established a number of Forts on the Great Lakes and engaged in a series of battles against the English and the Iroquois.

In his first term, he supported the expansion of the fur trade, establishing Fort Frontenac (in what is now Kingston, Ontario) and came into conflict with the other members of the Sovereign Council over its expansion and over the corvée that were required to build the new forts. In particular, despite the opposition of Bishop François de Laval, he supported selling brandy to the aboriginal tribes, which Laval considered a mortal sin. The conflict with the Sovereign Council led to his recall in 1682.

His second term was characterised by the defence of Quebec from an English invasion during King William's War, a successful campaign against Iroquois and English settlements that resulted in the elimination of the Iroquois threat against New France and a large expansion of the fur trade using Canadian coureurs des bois. He died before his second recall to France.

Frontenac was born in Saint-Germain-en-Laye, France, the son of Henri de Buade, colonel in the regiment of Navarre, and Anne Phélypeaux, daughter of Raymond Phélypeaux. The details of his early life are meager, as no trace of the Frontenac papers has been discovered. The de Buades, however, were a family of distinction in the principality of Béarn. Antoine de Buade, seigneur de Frontenac, grandfather of the future governor of New France, attained eminence as a councilor of state under Henri IV; and his children were brought up with the dauphin, afterwards Louis XIII.

Frontenac entered the army at an early age. In 1635 he began his military career and he served under the prince of Orange in Holland, and fought with credit and received many injuries during engagements in the Low Countries and in Italy. He was promoted to the rank of colonel in the regiment of Normandy in 1643, and three years later, after distinguishing himself at the siege of Orbetello, where he had an arm broken, he was made maréchal de camp. In the 17th century, warfare ceased during the winter months, and Frontenac, being a soldier, needed to keep occupied. Like many military officers, Frontenac took residence at the King's court. Such a lavish lifestyle proved to be costly, and his time at the King's court only led him to amass more debt. His growing debt led him to seek an arrêt du Conseil d'état later in his life to protect his properties from his creditors, who otherwise would have been able to seize them.

His service seems to have been continuous until the conclusion of the Peace of Westphalia in 1648, when he returned to his father's house in Paris and married, without the consent of her parents, Anne de la Grange-Trianon in October 1648. Frontenac courted her because she was set to inherit a large sum of money from her deceased mother and her father upon his death. Anne de la Grange-Trianon's father had remarried and had a second child to ensure that his fortune would not go to his daughter and the son-in-law that he disapproved of. Therefore, when Frontenac's father-in-law died, Frontenac did not receive the money he was hoping for as his wife's father left his fortune to his new wife. The marriage was not a happy one, and after the birth of a son incompatibility of temper led to a separation, the count retiring to his estate on the Indre, where by an extravagant course of living, he became hopelessly in debt. Little is known of his career for the next fifteen years beyond the fact that he held a high position at court, but in 1669, when France sent a contingent to assist the Venetians in the defense of Crete against the Ottomans, Frontenac was placed in command of the troops on the recommendation of Turenne. In that expedition he won military glory, but his fortune was not improved.

In 1664, Frontenac admitted to owing debt of 325,878 livres, plus 17,350 livres of interest to his creditors, which had not been repaid by 1672, when his property was seized by creditors. Frontenac, however, was offered the position of governor-general of New France which deferred his debts until the end of his governorship. Frontenac was appointed governor and lieutenant general of New France, Acadia, the island of Newfoundland on 6 April 1672 and arrived in Quebec on 7 September that same year.

A 17th-century painting of Anne de la Grange-Trianon can be seen at the Château de Versailles.