Pierre Mazeaud, born August 24, 1929 in Lyon's 4th arrondissement, is a French lawyer, politician, and mountaineer. From 1968 onward, he served at various times as a Gaullist MP, Vice-President of the National Assembly, Secretary of State, State Councilor, member, and then President of the Constitutional Council until March 2007.

Pierre Mazeaud's family includes several well-known lawyers. He had a difficult high school career. Expelled from middle school to high school, he earned his baccalaureate and earned a law degree and then a doctorate in law in 1955. At the beginning of his law studies, he joined the Anarchist Federation (FA) and became a member of its student committee. He then wrote for Le Libertaire under the pseudonym Pierre Hem. He wrote 11 articles between July 14, 1950, and May 25, 1951, on student struggles, anti-colonialism, and defending the "third front" strategy ("Neither Stalin nor Truman") advocated by the FA. Pierre Mazeaud belonged to two worlds largely alien to each other: the world of politics and that of mountaineering. Coming from a line of aristocrats from the universities and the judiciary, Mazeaud was the opposite of the bourgeois spirit that thrives today like never before. He was an important political figure of the Fifth Republic and one of the few—on the right, no less!—to have belonged to and flourished within one of the few remaining transclassist circles: that of mountaineering, which brought together young people from all walks of life, choosing to tackle the still-untouched routes and faces of the Alps, sometimes at the cost of their lives or even loss.

Pierre Mazeaud is known for his freedom of tone, ideas, and expression, due to his youth as a very active anarchist activist. His strong character and the strength of his convictions do not alter his sense – never found wanting – of friendship, a sense probably forged in the routes opened in the Mont Blanc massif. These climbs taught him the value of human trust necessary in the mountains, and dedicated a friendship of several decades with the great Italian mountaineer Walter Bonatti, an undeniably major figure in the history of mountaineering, and to whom Mazeaud readily says that he owed his life in 1961. He will make several first major ascents in the company of the greatest names in post-war mountaineering: René Desmaison, Walter Bonnatti, Robert Paragot and Lucien Bérardini among others, in the Alps, the Himalayas, the Algerian Sahara, etc. "I experienced my greatest joys in the mountains. And it can make you smile; I found friendship there, and that's something. More than politics, more than my work as a lawyer, the mountains were my passion to the very end."

In 1998, Pierre Mazeaud proposed that the fight against racism be included in the preamble to the Constitution. A leading figure in the National Assembly and French political life, he was an extraordinary figure, at once a scrupulous jurist, a stormy orator, and a man of conviction with a strong enough character to leave no one indifferent, nor to remain silent when a fundamental issue, in his view, emerged in the debate. In 2021, his visits to the Palais Bourbon saddened him, and his hatred of the far right was exacerbated.