Abu Hatim al-Razi: Imam, and he once said: If you see a Baghdadi hating Yahya ibn Ma'in, then know that he is a liar
Abu Hatim ibn Hibban al-Busti: Knowledge by which one is guided in narrations, and an Imam to whom one refers in matters of hadith
Abu Dawud al-Sijistani: Scholar of men
Abu Sa'd al-Sam'ani: He was a righteous Imam, scholar, hafiz (one who has memorized the Quran), firm, precise, and referred to in matters of Jarh wa al-Ta'dil
Abu Sa'id al-Haddad: People are dependent on Yahya ibn Ma'in in hadith
Abu 'Abd Allah al-Hakim al-Nishapuri: Imam of the people of hadith, and a purifier of narrators without any opposition
Ahmad ibn Hanbal: He was the most knowledgeable of us in men, and once: A man whom Allah Almighty created for this matter, he exposes the lies of liars, and once: Every hadith that he does not know is not a hadith
Ahmad ibn Shu'ayb al-Nasa'i: He is Abu Zakariya, the trustworthy, the reliable, one of the Imams in hadith
Ahmad ibn Salih al-Jili: Allah Almighty did not create anyone who was more knowledgeable in hadith than Yahya ibn Ma'in
Ibn Hajar al-'Asqalani: Imam of Jarh wa al-Ta'dil, trustworthy, hafiz, famous
Al-Khatib al-Baghdadi: Righteous Imam, scholar, hafiz, firm, precise
Al-Dhahabi: The Hafiz, Imam of the hadith scholars, and once: Imam of Jarh wa al-Ta'dil, trustworthy, hafiz, famous
Al-Qasim ibn Salam al-Harawi: The righteous of hadith are four: The most knowledgeable of them in authentic and weak hadith is Yahya ibn Ma'in
Al-Mizzi: Imam of the people of hadith in his time, and the one referred to among his peers
Salih ibn Muhammad al-Jazara: The most knowledgeable of those I met in verifying the Sheikhs, and once: More knowledgeable in men and kunya than Ahmad ibn Hanbal
Abdullah ibn Muhammad al-Ramli: There is no one like him in the world, he preceded people in this field, no one preceded him to it, and once: I have not seen anyone who speaks the truth about the Sheikhs except Yahya, and others would be biased in their speech, and once: He recognizes errors
Ali ibn al-Madini: Knowledge ended with al-Zuhri, 'Amr ibn Dinar, al-A'mash, Abu Ishaq, Qatada, and Yahya ibn Abi Kathir. I found the knowledge of these people ended with Yahya ibn Ma'in, and once: We do not know anyone since Adam who wrote from the hadith what Yahya ibn Ma'in wrote
Amr ibn 'Ali al-Fallas: There was no one among our companions more knowledgeable in isnad than him. No one could ever reverse an isnad on him
Muhammad ibn Ismail al-Bukhari: I never felt insignificant except in the presence of Yahya ibn Ma'in
Muhammad ibn Sa'd al-Waqidi: He wrote a lot of hadith and was known for it, and he hardly ever narrated
Muhammad ibn Harun al-Fallas: If you see a man criticizing Yahya ibn Ma'in, then know that he is a liar who fabricates hadith. He only hates him because he exposes the liars
Yahya ibn Sa'id al-Qattan: No one like him has come before us