The former Muftee of the kingdom of Saudi Arabia, Shaikh Muhammad bin Ibraheem Aali Shaikh (rahimahullaah) said:

And he is the upholder of the Sunnah, a supporter of the truth and an opposition to the people of falsehood.

During his lifetime, the father, the Shaikh, ‘Abdul-Azeez bin Baaz (rahimahullaah) said:

I have not seen anyone under the surface of the sky with more knowledge of the Hadeeth in our current time than the likes of the great scholar, Muhammad Naasir-ud-Deen Al-Albaanee.

And he (rahimahullaah) was asked about the hadeeth of the Prophet, sallAllaahu ‘alayhi wa sallam:
“Indeed Allaah raises up from this ummah at the beginning of every century someone who will revive it for them (i.e. a mujaddid).” So he was asked who is the mujaddid of this century? He replied: “Shaikh Muhammad Naasir-ud-Deen Al-Albaanee. He is the mujaddid in my opinion and Allaah knows best.

Shaikh Muhammad bin Saalih Al-‘Uthaimeen (rahimahullaah) said:

From what I came to know of the Shaikh through my gatherings with him – and they were few – was that he was very serious about acting upon the Sunnah and fighting against the innovations, whether in matters of Belief or in matters of actions. As for through my readings of his written works, then I have come to know that about him, and also that he possesses a vast amount of knowledge of Hadeeth, in terms of reporting them and investigating them. And Allaah has benefited many people through what he has written such as about knowledge, aspects of the Manhaj, and concern for the science of Hadeeth. And this is an enormous result for the Muslims, all praise be to Allaah.

Shaikh Muqbil bin Haadee Al-Waadi’ee (rahimahullaah) said:

Indeed, there cannot be found an equal in terms of the knowledge of hadeeth like that of Shaikh Muhammad Naasir-ud-Deen Al-Albaanee. Allaah has given benefit through his knowledge and his books several times more than what has been accomplished by those zealots for Islaam upon the
ignorance of those who organize reformation and revolutionary movements. And that which I sincerely believe in and which I owe my thanks to Allaah for is that the Shaikh Muhammad Naasir-udDeen Al-Albaanee is from the mujaddideen (reformers/revivers) whom the Prophet, sallAllaahu ‘alayhi wa sallam, spoke the truth of when he said: “Indeed Allaah raises up from this ummah at the beginning of every century someone who will revive it for them (i.e. a mujaddid).” Reported by Abu Dawood and authenticated by Al-‘Iraaqee and others.”