The majority of scholars have allowed broad scope in the naming of mosques; thus they have permitted calling them anything that will distinguish them from one another, such as the names of Prophets, scholars, the righteous, the names of those who built them, the names of countries or cities in which they are located, or the tribes who live in those areas, and so on. They quote as evidence for that the report narrated in Saheeh al-Bukhaari (no. 420) which states that one of the mosques was called Masjid Bani Zurayq. This has been discussed in the answer to question no. 71301.
We will quote here from the Fatwas of the Standing Committee (vol. 2, 5/280-284), a lengthy fatwa that has to do with this topic:
By studying the names of mosques we found that their names may be categories as follows:
1. Named after the one who built it. This comes under the heading of attributing righteous deeds to those who do them and is also a name that is based on some facts and serves to differentiate between mosques. This is permissible. Examples include Masjid al-Nabi or the Mosque of the Prophet (peace and blessings of Allaah be upon him), which is also called Masjid Rasool-Allaah or the Mosque of the Messenger of Allaah (peace and blessings of Allaah be upon him).
2. Named after those who pray in it [i.e., the tribe, congregation, neighbourhood who usually pray in it], or after the place, which is also a name that is based on some facts and serves to differentiate between mosques. This is also permissible. Examples include: Masjid Quba’, and Masjid Banu Zurayq, as mentioned in al-Saheehayn in the hadeeth of Ibn ‘Umar (may Allaah be pleased with him) which mentions the race to Masjid Bani Zurayq and Masjid al-Sooq. Al-Bukhaari included it in a chapter entitled Chapter of the scholars in Masjid al-Sooq.
3. Named after a distinguishing characteristic, such as al-Masjid al-Haraam and al-Masjid al-Aqsa, as in the aayah in which Allaah says (interpretation of the meaning): “Glorified (and Exalted) be He (Allaah) [above all that (evil) they associate with Him] Who took His slave (Muhammad صلى الله عليه وسلم) for a journey by night from Al‑Masjid Al‑Haraam (at Makkah) to Al‑Masjid Al‑Aqsa (in Jerusalem)” [al-Isra’ 17:1]. In the Sunnah it is proven via several isnaads that the Prophet (peace and blessings of Allaah be upon him) said: “Mounts are not to be prepared for travelling to any mosques except three: al-Masjid al-Haraam, al-Masjid al-Aqsa and this mosque of mine.” Another example is al-Masjid al-Kabeer. One of the mosques on the route between Makkah and Madeenah is called al-Masjid al-Akbar, as it says in Saheeh al-Bukhaari; similarly a mosque may be called al-Jaami’ al-Kabeer.
Calling a mosque by a name that is not connected to any facts in order to distinguish it and by which it may be known is a phenomenon that is widespread nowadays because many mosques are being built, praise be to Allaah, in Muslim lands, in cities and in villages, even in a single neighbourhood. So mosques are given names to distinguish them, and names are chosen to call the mosque after one of the prominent figures of Islam among the Sahaabah (may Allaah be pleased with them) and the Taabi’een who followed them in truth, such as Masjid Abi Bakr (may Allaah be pleased with him), Masjid ‘Umar (may Allaah be pleased with him) and so on, to distinguish them from one another. There does not seem to be anything wrong with giving mosques names like these, especially since it is known that the Prophet (peace and blessings of Allaah be upon him) gave names to his weapons, furnishings, mounts and clothes, as was stated by Ibn al-Qayyim (may Allaah have mercy on him) at the beginning of his book Zaad al-Ma’aad.
Naming a mosque after one of the names of Allaah, may He be glorified and exalted, such as Masjid al-Rahmaan, Masjid al-Quddoos, Masjid al-Salaam. It is well known that Allaah said (interpretation of the meaning): “And the mosques are for Allaah (Alone), so invoke not anyone along with Allaah” [al-Jinn 72:18]. All the mosques are for Allaah, without needing to be singled out, so calling a mosque by one of the names of Allaah so as to distinguish it from other mosques is an innovated matter which was not done in the past, so it is better not to do it. And Allaah is the guide to the straight path. End quote from Fataawa al-Lajnah al-Daa’imah.
See the book Ahkaam al-Masaajid (2/86) by Ibraaheem al-Khudayri.
Based on the above, the basic principle is that there is nothing wrong with calling a mosque Masjid Ahl al-Hadeeth, as it is naming it after an acceptable and legitimate characteristic. This name, among the scholars, is a kind of praise and mentioning something good, so calling a mosque by this name is something sound and there is nothing wrong with it, in sha Allaah.
This ruling has to do with the general principles, but before applying it to your mosque, we should look at the situation in your land. If attributing yourself to Ahl al-Hadeeth, or calling yourself by their name, or calling your mosque “Ahl al-Hadeeth” will result in creating division among the Muslims, or stir up resentment in their hearts, or revive jaahili tribalism and create fitnah and troubles among the Muslims, then it is better not to use this name, and even avoid permissible matters of higher importance if doing them will result in any of these evils. All that can be said about giving your mosque this name is that it is a permissible matter that you decided to give up. Among the permissible names you have those that will unite people and not cause division, names that will attract people and not put them off, and that should be sufficient. The Prophet (peace and blessings of Allaah be upon him) denounced calling with permissible names if the motive is fanatical devotion to anything other than the truth.
It was narrated that Jaabir ibn ‘Abd-Allaah (may Allaah be pleased with him) said:
We were with the Messenger of Allaah (peace and blessings of Allaah be upon him) on a campaign, when a man of the Muhaajireen hit a man of the Ansaar from behind. The Ansaari said: O Ansaar! And the Muhaajir said: O Muhaajireen! The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “What is this call of Jaahiliyyah?” They said: O Messenger of Allaah, a man of the Muhaajireen hit a man of the Ansaar from behind. He said: “Stay away from it, it is disgusting.”
Narrated by al-Bukhaari (3518) and Muslim (4682).
Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said:
These two names – Muhaajireen and Ansaar – are Islamically acceptable names which are mentioned in the Qur’aan and Sunnah, and Allaah called them by these names, as Allaah calls us Muslims. For a man to attribute himself to the Muhaajireen and Ansaar is something good and praiseworthy before Allaah and His Messenger. It is not only permissible for the purpose of distinction, such as when one attributes oneself to a tribe or country; it is not something disliked or haraam, such as when one attributes oneself to something that may lead to bid’ah or sin. Nevertheless, when each of them called a group to help him, the Prophet (peace and blessings of Allaah be upon him) denounced that and called it the call of Jaahiliyyah, until it was said to him that those who were giving this call were young men, and that did not come from the group, in which case he ordered that the wrongdoer be stopped and the one who was wronged be helped.
Iqtida’ al-Siraat al-Mustaqeem (71)
And Allaah knows best.