The Unreached Clusters of Southeast Asia

“People group clusters” are groups of individual peoples clustered based on language and ethnic affinity. Worldwide, there are 252 clusters; 113 of these are considered least-reached. In this article, we focus on those in Southeast Asia.1

Southeast Asia is made up of ninety-two clusters, totaling roughly 567 million people. One-third of the world’s people group clusters are found in this region. Of these, forty (nearly half) have over ninety percent of their population within Southeast Asia. Eighteen clusters are immigrants, with fewer than twenty percent of their numbers in Southeast Asia.

For brevity, we will focus primarily on those which have more than ten million members. We will then look briefly at those with less than ten million members. The ten largest clusters include:


Number of members 

Vietnamese  73 million 
Central Filipino  70 million 
Jawa  58 million 
Thai 51 million   
Malay 46 million   
Sunda-Betawi    33 million
Chinese    32 million 
Burmese    32 million 
Madurese    21 million 
Mon-Khmer   21 million  

With the exception of the Chinese and the Mon-Khmer, over ninety-five percent of each of these groups reside in Southeast Asia. However, because of their size, even five percent residing abroad can result in significant numbers.

Vietnamese. The Vietnamese cluster is made up of just two groups: the Vietnamese themselves as well as the twenty-nine thousand Jing. The Vietnamese are found in twenty-eight countries. Some 72.6 million are found in Vietnam itself, another one million are found within the region (in Cambodia, Laos, Malaysia, and Thailand), and the remaining three million are outside the region, mostly to France (600,000) and the United States (1.2 million). Reaching the Vietnamese, then, involves reaching Vietnam. Fortunately, this country is becoming more open; however, one should not neglect the migrant populations in the US and France. The Vietnamese cluster has significant work going on, but it is still majority Buddhist. To fully engage this cluster will likely require 730 pioneering swarming teams.2

Central Filipino. The seventy million Central Filipino cluster includes twenty-seven peoples. The largest groups within the cluster are the Tagalog speakers, the Ilocano, and the Visayan (each with more than ten million people), as well as the Central Bikol, Hiligaynon, Mestizo, Pampango, Pangasinese, and Waray-Waray. There are also a number of smaller groups. This cluster is considered reached, and missionaries from this cluster are being recruited and sent elsewhere.

Jawa. The fifty-eight million Jawa cluster is made up of just nine people groups, including the fourteen million Javanese, five million Jawa Banyumasan, twelve million Jawa Mancanegari, three million Jawa Pesisir Kulon, and twenty-two million Jawa Pesisir Lor. All of these (except the Javanese) are unreached. While the Javanese have spread to ten countries (including some in Europe), all of the least-reached peoples within this cluster are found in Indonesia itself. Some 580 pioneering swarming teams would likely be required to fully engage the group; a very large effort is already going on.

Thai. The fifty-one million Thai cluster is comprised of two very large groups (the Northeastern Thai and the Central Thai), two megapeoples (the Northern Tai and the Southern Tai), and three smaller groups (the 521,000 Khorat, as well as several thousand Tak Bai and Tsun-Lao). All of these are unreached. While there are many efforts being made to reach the Thai, these efforts are not enough, considering the enormous size of these groups. It will take perhaps 510 pioneer swarming teams to fully engage the groups. Most effort is taking place in the northern part of Thailand and there are many regions of the country that are virtually untouched. While the Thai are mostly found in Thailand itself, several small groups can be found in surrounding countries as well as in Western nations such as the United States and Canada.

Malay. The forty-six million Malay are diversified and made up of some forty-one groups. The four largest are the twenty-six million Indonesians, twelve million Malay, three million Pattani Malay, and two million Orang Pantai Timur.

The remaining groups have a population of less than twenty thousand people, with the exception of the East Malaysian Malays (269,000), Kota Bangun Kutai (120,000), Menadonese (115,000), and Riau (114,000). Although ethnic religions still dominate them, virtually all of the very small groups have been reached. The larger groups are all majority-Muslim. Some 460 pioneer swarming teams will be required to fully engage this cluster. There is substantial work among Indonesians and among the smaller groups; however, the remainder of the Malay groups have comparatively very little work going on.

Sunda-Betawi. The thirty-three million Sunda-Betawi cluster is, like the Jawa cluster, located primarily on the Indonesian island of Java. Very few migrants from this cluster have moved abroad. It is comprised of just four groups, three of which are unreached. The groups include the thirty million Sunda, 3.6 million Betawi, and two smaller groups: the Badui and the Sunda-Banten. Islam is the dominant religion. It would take perhaps 340 pioneering swarming teams to fully engage them. There are significant partnerships focused on this cluster; however, much remains to be done.

Chinese. The thirty-two million Chinese cluster, on the other hand, is a largely expatriate population that has settled into the region and become part of it. While ninety-six percent of all the groups in the Chinese cluster reside inside East Asia (mainly in China itself), the Chinese within Southeast Asia (2.6% of all Chinese globally) are the second largest concentration of Chinese in the world and over half of all expatriate Chinese. Perhaps 320 pioneering swarming teams are needed to fully engage this population; fortunately, there is much going on among the Chinese of Southeast Asia, with numerous churches and evangelistic efforts. Indeed, some of the largest and most well established churches in Southeast Asia are among Chinese.

Burmese. The thirty-two million Burmese cluster is made up of eight people groups, the largest of which is the twenty-nine million Burmese itself. The two other megagroups include the 2.2 million Arakanese and the 1.1 million Yangbye. Over ninety-eight percent of the cluster is in Southeast Asia. The groups within the cluster are majority Buddhist, and all are unreached. The cluster needs perhaps 320 pioneering swarming teams. Surging Buddhist influence and governmental instability in Myanmar is providing both challenges and opportunities for the gospel as well as public visibility for the nation.

Madurese. The twenty-one million Madurese cluster is another Indonesian cluster. It is made up of four people groups, three of which are unreached. The two largest are the Madurese and the Pendalungan. All are majority-Muslim groups living primarily on the island of Madura and Java. Some expatriate Madurese also live in Singapore. The Madurese cluster needs perhaps two hundred pioneer swarming teams. There is significant local work on this need.

Mon-Khmer. Finally, we need to look at the Mon-Khmer cluster. Unlike the other clusters, the Mon-Khmer is made up of over 150 separate peoples. Out of the twenty-four million Mon-Khmer, twenty-one million reside in Southeast Asia. Of the 150 groups, ninety-six are unreached. Most of these groups are ethnoreligionists or Buddhists. The three largest are: the fourteen million Khmer, the 1.3 million (mostly Christian) Khasi, and the 1.2 million Muong. Two other large groups include the Mon (878,000) and the Wa (845,000). More than three hundred pioneering swarming teams would be needed to fully engage this cluster. While most are found in only one or two countries, the Khmer are found in Cambodia, Vietnam, the United States, and several European countries. Still, reaching the Khmer will mean ultimately reaching Cambodia itself.

Smaller “Megaclusters”
In addition to these large clusters, there are nearly thirty “megaclusters” consisting of populations between one million and ten million each. Over half of these are unreached. The Minangkabau-Rejang, Bugi-Makassar, Bali-Sasak, Melayu, Banjarese, Filipino Muslims, Shan, Lampung, and Acehnese have more than four million people. Many of these megaclusters are majority Muslim. Exceptions include the ethnoreligionists (Borneo-Kalimantan, Tai, Zhuang, Miao/Hmong, and Cham), the Buddhists (Shan and Lao), and the Hindus (Bali-Sasak, on the Indonesian island of Bali, and the Tamil speakers, who are spread throughout the region). Collectively, these clusters account for over 115 million people and will require perhaps three hundred pioneering swarming teams to fully be engaged.

Beyond these megaclusters, there are an additional ten million people in smaller clusters with populations under one million in Southeast Asia. Many of these are migrant groups.

The situation in Southeast Asia is complex. There are national partnerships and significant efforts underway; however, much more needs to be done. If you want to make a difference, why not connect with one of these partnerships or networks, and collaborate to create a pioneer team among one of these clusters?


1. For the purpose of this analysis, I will be using the publically available Joshua Project data, backed up by information from the World Christian Encyclopedia and the subscription-based World Christian Database.

2. For more information on swarming and swarming teams, visit

Justin Long manages and is senior editor for Momentum, a magazine devoted to unreached peoples. He can be reached at [email protected].