Mr Pierre Rousseau was born in Châtillon-en-Bazois, Nièvre, Burgundy, France on 13 October 1863.

He was the son of Jean Rousseau (1816-1899) and Anne Durand (1825-1898).

He was married to his wife, the former Alice Bazin (b. 1862), possibly in the early 1880s and their daughter Berthe was born in France in 1885. The family later relocated to England an appear on the 1901 census living at 31 Halsey Street, Chelsea, London and Pierre was described as a cook "not domestic."

Pierre had reportedly worked as chef at the Belgravia, Trocadero, Crystal Palace, North British Station Hotel in Edinburgh, as well as one or both of Luigi Gatti's London restaurants. He was selected to join employees from the Gatti restaurants to staff White Star Line's new ship Olympic in 1911. He was then transferred to Titanic for her maiden voyage and signed on to the ship on 6 April 1912; his address at the time was 7 Frederick Mews, Knightsbridge, Middlesex.

During the sinking there were reports that the largely continental staff of the restaurant, mainly French, Italian, Swiss, German and Belgian, were herded to their quarters by stewards and detained there. Indeed, only three from the staff survived, two of whom were the female cashiers.

Rousseau's secretary Paul Maugé had made a reconnaissance of the boat deck shortly after collision and saw the lifeboats being prepared and returned to his quarters. Encountering Rousseau he told him of the situation and the chef lost his temper and became agitated. He and Maugé, both dressed in their civilian clothes were, at that time, standing somewhere between their own quarters and the third class accommodation at the aft-end of Scotland Road; they made for the doors that led to the (presumably) aft second class staircase but a group of four to six stewards guarding that entrance held the men back. Maugé protested and he and Rousseau were allowed to pass through but he stated that the other restaurant staff nearby were not afforded that same luxury; he and Rousseau apparently waited around in the second class stairwell area for up to half an hour and saw no more of the restaurant crew pass through.

Rousseau and Maugé eventually arrived at the boat deck and positioned themselves on the starboard side where several boats were still in preparation, some if not all flush with A-deck and receiving passengers from there. One boat (believed to have been boat 13 but not certain) began lowering and a crowd of what Maugé estimated to be between 6-10 men began throwing themselves from the boat deck into the boat and, spying an opportunity, Maugé decided he and Rousseau should do the same and suggested this to his chef. Rousseau, a large man, refused presumably on accounts of his weight, but Maugé entreated him before jumping over the side and landing in the boat, repeatedly calling out "sautez!" Rousseau shouted something out to him but Maugé could not hear what he said as the boat was lowered.

Pierre Rousseau died in the sinking and his body, if recovered, was never identified. His estate, worth £713, 13s, 4, was administered to his widow Alice on 22 May 1912.

What became of Rousseau's widow and daughter is not known.