Rabbi Pinchas ben Yair was a Tanna of the late 2nd century, of the fourth-fifth generation, who probably lived in Lod. He was a Kohen. According to the Talmud (Shabbat 33b) he was the son-in-law of Rabbi Shimon bar Yochai, while the Zohar presents him as his father-in-law; some commentators suggested that there were two sages of this name. He was a colleague of Rabbi Yehuda HaNasi, whom he dissuaded from abolishing the shemitah year. More celebrated for piety than for his halachic teaching, which does not appear in the Mishnah, he nonetheless showed great sagacity in his discussions with Rabbi Shimon.

The Talmud says of him that "in all his days he never broke bread over a slice that was not his own, and from the time he reached maturity he did not benefit from his father's meal" (Chullin 7b). Once invited by Rabbi Yehuda HaNasi, he turned back on seeing dangerous white mules in the courtyard. He excelled in the mitzvah of redeeming captives, at a time when, after the Bar Kochba revolt, many Jews had been sold into slavery, and in scrupulous tithing: the Midrash relates that his donkey, once stolen, refused to eat barley from which tithes had not been taken. The Talmud also tells that the River Ginai split before him when he set out to redeem captives, and that he told his students that only one who has never wronged anyone may cross it that way. When two men deposited two measures of wheat with him, he sowed it and preserved the harvests for seven years, then returned to them all the accumulated grain.

He painted a somber picture of his era: "Since the destruction of the Temple, scholars and free men are ashamed and cover their heads, men of deeds are diminished, the violent and the informers prevail... On whom can we rely? On our Father in Heaven" (Mishnah Sotah 9:15). He is best known for his "ladder of holiness": "Torah leads to watchfulness, watchfulness to zeal, zeal to cleanliness, cleanliness to abstinence, abstinence to purity, purity to piety, piety to humility, humility to fear of sin, fear of sin to holiness, holiness to the holy spirit, and the holy spirit to the resurrection of the dead" (Avodah Zarah 20b). This teaching is the foundation of the Ramchal's Mesillat Yesharim. The Midrash Tadshe, also called the Baraita of Rabbi Pinchas ben Yair, is attributed to him.

According to the tradition reported in the name of the Arizal in Emek HaMelech, he rests in the old cemetery of Safed, at the bottom of the hill, under a pile of stones without a monument, since in his lifetime he never benefited from the money of others. It is customary to circle his grave seven times, a practice recorded by the Munkatcher Rebbe.