There are 1.2 million citizens and 2.6 million non-citizens. In 2001, there were 1125,000 Sunni Kuwaiti citizens, 130,000 Shia Kuwaiti citizens and 920,000 Kuwaiti citizens in total thus Sunnis formed 84% and Shias formed 13.5% of the Kuwaiti citizen population. In 2002, the US Department of State reported that Shia Kuwaitis formed 10–15% of Kuwait's citizen population, noting there were 525,000 Sunni Kuwaiti citizens and 855,000 Kuwaiti citizens in total (87% Sunnis, 13% Shias). In 2004, there were 600,000 Sunni Kuwaitis citizens, 300,000–350,000 Shia Kuwaiti citizens and 913,000 Kuwaiti citizens in total. There is also a small number of Ahmadi Muslims in Kuwait.
There are also Christian Kuwaiti citizens. There are between 200 and 400 Christian Kuwaiti citizens. In 2014, there were 259 Christian Kuwaiti citizens residing in Kuwait. There is also a small number of Bahai Kuwaiti citizens. An estimated 150,000 noncitizen residents are Shia. While some areas have relatively high concentrations of either Sunnis or Shia, most areas are religiously well integrated.
There are an estimated 600,000 non-citizen Hindus. The non‑citizen Christian population is estimated to be more than 450,000. The government-recognized Christian churches include the Roman Catholic Church, the Coptic Orthodox Church, the National Evangelical Church Kuwait (Protestant), the Armenian Orthodox Church, the Greek Orthodox Church (referred to in Arabic as the Roman Orthodox Church), the Greek Catholic (Melkite) Church, and the Anglican Church. There are also many unrecognized Christian religious groups with smaller populations. There are an estimated 100,000 Buddhists, 10,000 Sikhs, and 400 Bahais, the majority of whom are non-citizens.