Because most well-known examples of fictional Muslim characters and settings in mainstream media tend to be from North Africa and the Middle East, there is an assumption that Muslims are all Arabs or speak Arabic as their main language. This is despite the fact that the largest Muslim population in the world is in Indonesia, which is located in Southeast Asia, and many Muslims come from all over Asia (as a matter of fact, the region with the largest number of Muslims overall is in fact, South Asianote , which has more than 630 million Muslims. Meanwhile, the Middle Eastnote has less than 410 million Muslims), Africa, and Europenote and do not consider themselves Arabs. Even within the Middle East exist a multitude of ethnic groups who practice Islam and speak a variety of different languages, such as Kurdish, Persian, and Turkish which belong to totally different language families from Arabic.note Likewise, North Africa — another region that has been largely Arabised in terms of language and culture — still has plenty of people who identify more with the pre-existing Amazigh/Berber languages and cultures, and the line between "Arab" and "Amazigh" can be blurry there.
The trope most often affects Iran and Turkey, two emerging markets and regional powers who frequently make international headlines, as they happen to be (1) Middle Eastern, and (2) majority-Muslim. Even Muslims from far-off places sometimes lump them both as Arab countries, because, barring their distinct languages, their culture do overlap a bit with their Arab neighbors and you have to be rather well-versed in Middle Eastern studies to be able to distinguish them, something that the common folk just don't care, it seems. To make matters worse, Iran officially writes using the Arabic script,note a legacy of when it was ruled by Arabs more than a millennium ago. Turkey's situation is a bit better, but then you will run into problems of explaining exactly what Turkish culture is, especially as their language is not only alien to the West but also the Middle East itself. In the region, Turkey has a love-hate relationship with the Arab countries, because it used to rule vast swathes of the Arab world for centuries; needless to say, some Arabs still regard Turkey and Turks in general as a colonizer. As for Iran... well, as the page quote shows, it's best not to lump it with Arabs. Really. If you want a picture, imagine the Greeks' view of themselves compared to Turks, but magnified tenfold. Iranians will happily lecture you on how magnificent their culture is and how long their history dates back if you do so.
Complicating this issue is that scholars of Islam are expected to learn Classical Arabic in order to understand the Quran, since there are no official translations into other languages due to the belief that some of the meaning would be lost in translation; therefore Muslims who take their faith seriously often do understand Arabic in some form, even if it is not their main tongue. Cultural influences also mean that many non-Arab Muslims understand and use Gratuitous Arabic phrases in everyday life (e.g. Assalamualaikum, a catch-all greeting; or Alhamdulillah, the equivalent of and used in the same situation as "Hallelujah"), which might create the assumption that all Muslims know Arabic, when in fact, they do not.
Compare Latino Is Brown, All Jews Are Ashkenazi. The inverse of "All Arabs are Muslim" is also a massive Berserk Button for Arab Christians and Jews, especially if they are from the Levant (Lebanon, Syria, etc.) given that their ancestors were likely practicing Christianity and Judaism in the faith's homeland far longer than anyone else. In fact, in some countries like Brazil, the Arab population that hails from the Levant is likely majority Christian instead of Muslim.
Note that this trope is not about the simple presence of Arab Muslims in a work, but rather about the implicit or explicit assumption that all Muslims are of Arab descent (e.g. by having Muslim characters speaking Arabic in casual conversation where their background and/or time period would make this improbable). Please do not add examples along the lines of "Character X is Arab" when it is nothing remarkable. Similarly, it's not worth listing an "aversion" if a work just happens to have a Muslim who is Indonesian, Turkish etc.
- In New X-Men, Dust speaks Arabic and wears a Saudi-style abaya and niqab, despite hailing from a poor region in Afghanistan, where she would be much more likely to speak Pashto or Dari and wear shalwar kameez, chador, or, if she is extremely conservative, burqa. Afghanistan does have an old Arab community, but they all speak Dari, the language they've been acculturated to for centuries. Made even weirder since they, for once, got her name right (unlike pseudo-Arabic names often employed by Western writers for their Muslim characters, Sooraya Qadir is culturally spot on).
- Although Ms. Marvel is Desi and speaks Urdu, ultimately avoiding this trope, it almost played it straight, as the author did admit that her first idea was to make making Kamala Arab. The series itself takes great effort to avoid this trope; of the various named Muslim characters introduced in its early run (Kamala's family who are Desi, Nakia who is Turkish, Kamran who is Persian, Tyesha who is African), all but one of them (Sheikh Abdullah) are explicitly non-Arab.
- In Crash (quoted above), a Muslim family's store is horribly vandalized, and anti-Muslim and anti-Arab slurs of spray-painted on the walls. Seeing this, the mother remarks that they are Persians, not Arabs.
- The Dictator has John C. Reilly's character Clayton looking forward to torturing General Aladeen because he's "an Arab", but Aladeen's nation Wadiya is located in the Horn of Africa, whose Arab population is minuscule compared to the majority Amharas, Oromos, Somalis, Tigrays, and Afars. Aladeen responds "I'm not Arab." And in any case Clayton is a horrible self-described racist who basically lumps all non-white people together as "Arabs".
- Zero Dark Thirty received some controversy from Pakistani audiences for, among other things, portraying community elders speaking in Arabic instead of their native Pashtun. This also applies in the outfits and background lines of the extras, seeing as how the Pakistan scenes were actually shot in Jordan.
- In a variation, Bohemian Rhapsody has a couple racist characters call Freddie "Paki", a typical slur in the UK for South Asians, and particularly ones who are Muslims. Freddie is not only not Pakistani (one of his first lines is to state this in an annoyed tone), he's not even Muslim (his family are Parsi, i.e. Indian Zoroastrians).
- Lampshaded in The Millennium Trilogy, where Dragan Armansky was born in Croatia, to an Armenian Jewish father from Belarus and a Bosnian Muslim mother of Greek heritage, and his Swedish immigration papers erroneously mark him as a Serbian, but because he is a practicing Muslim, he has acquired the nickname "The Arab".
- While this is true in NCIS: Los Angeles more often than not, one episode has Callen infiltrate a Muslim extremist cell led by a white Chechen and including at least one black American woman. It's mentioned by another Chechen, whom the team arrests at LAX so Callen can impersonate him, that he was sent precisely because of this trope: Americans expect Muslims to be brown, not white.
- Discussed in the second season of Ramy, which introduces several Black Muslim characters (Sheikh Malik and his daughter Zainab, the former of which is played by Mahershala Ali), who discuss some of the cultural differences between the Black and Arabic Islamic communities. There's also a white character, Dennis, who becomes an Islamic convert thanks to Ramy's influence. However, Dennis finds himself largely ostracized by the community after he assaults an anti-Muslim protestor.
- Invested in the Chilean television series Corazón Pirata, where an Arab family (possibly of Palestinian origin) constantly have to clarify that they are Arabs, not Turks. This is because the Arab immigrants who arrived in Chile at the beginning of the 20th century did so with a passport from the Ottoman Empire, when it still existed.
- Even though their capital is Astana, Kazakhstan and most of their strongholds are in central Asia, the GLA in Command & Conquer: Generals have Arab unit portraits and accents. They're never outright said to be Muslim, but the implication is clearly there in a lot of their imagery and dialogue.
- The Karachi map in Call of Duty: Modern Warfare 2 features all of its text in Arabic, despite the fact that Pakistan's official languages are English and Urdu.
- Call of Duty: Modern Warfare (2019) features a fictional Qurac where the characters mostly have Arab names and speak Arabic, but it has the "-stan" suffix in its name (which no Arab countries have) and is situated in the Caucasus Mountains, bordering Russia. North Caucasians are not Arabs and will be very annoyed if you mistake them for such. Also, despite being in the Caucasus, it somehow consists mostly of flat desert à la central Syria or Iraq.
- This trope was mostly true during the first century of Islam (circa 610-755 CE). Although there were some foreign converts (most notably, Salman the Persian), the Muslim community was by and large made up of the Arab tribe of Quraysh (to which Muhammad belonged) and their allies. Even when their territories spanned from Spain to India, Muslims did not form the majority beyond the Arabian Peninsula. This was self-inflicted; just as the settled societies (which made up a large chunk of the conquered lands) shunned the Arabs for their nomadic life, the Arabs did not have a high opinion of the settled societies, either. Although Islam preached for integration, the second Caliphate, the Umayyads, were particularly notorious for their Arab chauvinism, enforcing separation between themselves and the people they ruled. To them, all non-Arabs were beneath them, regardless of if they were Muslim or not. Therefore, there was no incentive for people to convert. It was not until they were overthrown by unsatisfied foreign Muslims (and some Defector from Decadence Arabs) and the much more open Abbasids (who were Persianized Arabs) installed that mass conversions took place and the non-Arabic-speaking Muslims outnumbered the Arabic-speaking ones.
- During the manhunt for the Boston Marathon bombers, a group of Redditors zeroed in on a pair of brown, apparently Muslim men in photographs from the crime scene. Barring the fact that the bombers were not Arabs, this was itself a Critical Research Failure; Arabs, as a cultural and linguistic group, span the whole spectrum of skin color, from the lightest white to the darkest black, and presenting some random brown-skinned people as Arabs was essentially meaningless. There was no other reason for it other than good ol' racial profiling. To avoid a witch hunt, the FBI decided to inform the public that the actual prime suspects, the Tsarnaev brothers, were white (Chechens, in fact "Caucasians" literally, as they were born in the Caucasus).
- An unintentional effect of the Black Lives Matter protests of 2020 was that Black Muslims became very vocal about the discrimination they face and how this trope occurs frequently even among other Muslims. One common complaint made by Black Muslims is that they are treated as not being Muslim enough because they are not Middle Eastern or South Asian.
- Truth in Television: As the language the Qur'an is written in, Arabic is regarded by Muslims worldwide to be an important language, and several hundred million Muslims have learnt Arabic as a foreign language to varying extents. They usually tend to add loads of Arabic loan words to their native languages too.