Source: UN World Population Prospects[11] Regarding the ethnicity of Bahrainis, a Financial Times article published on 31 May 1983 found that "Bahrain is a polyglot state, both religiously and racially.

[16] Of those, the vast majority come from South and Southeast Asia: according to various media reports and government statistics dated between 2005 and 2012 roughly 350,000 Indians,[17] 150,000 Bangladeshis,[18] 110,000 Pakistanis,[19] 40,000 Filipinos,[20] and 8,000 Indonesians.

[23] The following is a firm containing estimates from countries' embassies:[24] A 2024 study sequenced whole genomes from four individuals who lived in Bahrain during the Tylos period (circa 300 BCE to 600 CE).

One individual displayed a stronger affinity to Levantine populations, while others showed closer genetic links to groups from Iran and the Caucasus.

This timeframe coincides with the emergence of agriculture in the region, which could have inadvertently created environments conducive to malaria-carrying mosquitoes, thus driving natural selection for malaria resistance.

[26] Paternal population structure within Bahrain was investigated using the 27 Y-STRs (short tandem repeats) in the Yfiler Plus kit to generate haplotypes from 562 unrelated Bahraini males, sub-divided into four geographical regions—Northern, Capital, Southern and Muharraq.

[30][13] Unofficial sources, such as the Library of Congress Country Studies,[31] and The New York Times,[32] estimate sectarian identification to be approximately 45% Sunni and 55% Shia.

[5] Of these, 50.9% are Muslim and 49.1% are non-Muslim,[5] including Christians (primarily: Catholic, Protestant, Syriac Orthodox, and Mar Thoma from South India), Hindus, Buddhists, Baháʼís, and Sikhs.