What do you call a person who is regionally biased and has an unreasonable hatred/dislike for people from other regions of the country/world? Something like a racist, but the point of discrimination here is the geographical region and not race.
The word chauvinist used to mean exactly this. My impression is that this meaning is still valid, but it is possible that for younger people, this meaning has now been preempted by male chauvinism.
--3. very limited or narrow in scope or outlook; provincial: parochial views; a parochial mentality.
In its strict definition in the religious sense, it is neutral; however, in an extended meaning, it has negative connotations and is often used to mean exactly as 'regional bias'.
World English Dictionary defines parochial primarily as narrow in outlook or scope; provincial (see further down on the same page as above).
[Edit] Some citations:
... $2.6 billion saved by cutting numerous accounts that have in the past been slush funds for lawmakers back-home parochial projects. (AP, federal spending bill)
... domestic interest groups ... oppose policy innovations that would hurt their parochial interests. [Thomas J. Christensen in Foreign Affairs]
... by deepening their connections with the world, or whether they might instead become more parochial, more inward-looking, ... (Bill Emmott in Newsweek, Japan's catastrophe)
The award represented a high point of cosmopolitanism at a predictably parochial event: ... (AO Scott in NYT, Cinema Purgatorio)
The closest term I know is chauvinist.
I think parochial fits the bill.
Provincial is too mild, it lacks the castigation called for in the definition submitted by vr3690.
On the other hand, xenophobic appears somewhat harsh, given its association with racial attitudes.
Chauvinist could fit the bill. However, the term lacks the strong regional connotations required by vr3690's definition.
Insular could work. But I think the connotation of complacency dominates here. One is more a victim of one's own ignorance rather than a champion of one's own superiority.
That's why I'll go with parochial. Although the term has religious origins, in modern usage it has become sufficiently secularized to meet the implied definition of small-minded, local patriotism, not open to ideas beyond its limited horizons.
Another answerer already suggested this, but didn't provide any support for the answer, so I will "re-propose" regionalist.
Related definitions mainly focus on the form of the word expressing the ideology/outlook itself–regionalism:
A regionalist, then, would be someone with such an ideology/outlook.
Uses of the terms regionalism/regionalist tend to have a political bent, indicating an individual or group's "aim at increasing the political power and influence available to all or some residents of a region." Take, for example, its use here:
...a comparative analysis of the interaction between regional elites and national government in the antebellum American South and in the nineteenth-century Italian Mezzogiorno must pay particular attention to the specific case studies of South Carolina and Sicily, and specifically to the extreme regionalist ideologies that characterized the political demands of the South Carolinian and Sicilian elites and which eventually led to the comparable historical phenomena of secession and separatism.
Source: Agrarian Elites: American Slaveholders and Southern Italian Landowners, 1815-1861 by Enrico Dal Lago
However, regionalism isn't restricted purely to politics. It also takes the form of attempts at geographical/social/cultural/linguistic divisiveness as well:
Regionalists actively work for the spread and use of local dialects to the extent that Spanish is now taught as a second language in schools within the Spanish Catalunia. They fine shopkeepers who do not label their products in Catalan and/or physicians who do not write in Catalan. In France, the past is being revisited by activists, in the name of culture… with some ludicrous results.
These individuals and groups want to revert to Catalan, Basque or local dialect only, relegating French or Castilian to being second languages or erasing them altogether. ... To make it simple, if you do not speak Catalan, you do not “belong” to the territory in spite of your belongings or activity in the region.
Source: "Regionalism" by Vanessa Biard-Schaeffer
Taking regionalism to its extreme, regionalists could go from simple favoring of their own region, its people, its interests, and its properties, to dismissal/rejection of "people from other regions of the country/world," to outright hostility toward or even hatred of them.
To further emphasize the dislike/hatred aspect, you could say "hostile regionalist" or "extreme regionalist."
Nativism is the political position of demanding a favored status for certain established inhabitants of a nation as compared to claims of newcomers or immigrants