In a sociological context it could refer to the assimilation of ethno-cultural minorities in Sri Lanka such as the Sri Lankan Tamils, Colombo Chetties and indigenous Veddas into the majority Sinhalese identity, including some Sinhala Buddhists of the interior such as the Demalagattara and some Catholics such as the Bharatha of the coastal areas of the island nation.
In a political context it could refer to the Sinhala language-favouring policies [PS]of the post colonial governments of Sri Lanka that is considered to be a major cause  of the Sri Lankan civil war. It is termed as culturo-ideological exclusivism by some[who?] when one's cultural values and norms are absolutised in such a manner that a particular way of life is enshrined as superior to all others and must therefore be adopted by others (e.g. the Tamil reaction to the perceived "Sinhalisation" processes of the Sri Lankan state)
Medias use the word "Sinhalisation" to refer to the process by which the Sri Lankan government funded and sponsored settlement of Sinhala people in Tamil-dominant regions in order to make Tamil as minorities. Some reports claims that the Sinhalese and Sinhala military families are settled in houses built by money from the Indian government that was intended to improve the welfare of the Tamil people. 
^ elite: The late President J. R. Jayewardene's first paternal ancestor was a Colombo Chetty and there is an excerpt from the biography of J.R., authored by Prof. K.M. De Silva & Howard Wriggins, in support of this. Don Adrian Jayewardene, J.R.'s paternal great-grandfather, descended from a Chetty family, but two or three generations earlier, a male of this family had married a Sinhalese by the name of Jayewardene from the village of Walgama near Hanwella and had taken on the name of Jayewardene and by the time Don Adrian arrived on the scene at the tail-end of the 18th century, the process of 'Sinhalisation' of his family had been completed.
The ancestor of the Bandaranayke family was a 17th century Tamil immigrant Pandaram; a non-Brahmin priest known as Neelaperumal Kalukapuge. The term 'Kalu' in Tamil is different in meaning to the Sinhalese meaning.
A similar process was witnessed in the Kandyan kingdom, where for example the ancestor of Pilimatalavuva Maha Adikaram and related families trace or claim ancestry from a Pandyan emperor of the late 17th century, though the Pandyan kingdom had seized to exist by the 15th century and the region was ruled by the Madurai Sultanate, the Vijayanagara Empire and the Nayak dynasties.
^ PS: Sri Lanka’s nation-building programme became intimately linked with a Sinhalisation of the state directive. It was expected that the minorities would be assimilated into this new Sinhalese Buddhist nation-state. Moreover, the 1956 election marked the beginning of an era of ethnically-based party politics. 
- Susantha Goonetilleke, Sinhalisation: Migration or Cultural Colonization? Lanka Guardian Vol. 3, No. I, May I, 1980, pp. 22-29, and May 15 1980, pp. 18-19.
- Power and Religiosity in a Post-Colonial Setting: Sinhala Catholics in Contemporary Sri Lanka by R. L. Stirrat American Ethnologist, Vol. 22, No. 2 (May, 1995), pp. 428-429
- Buddhism Betrayed?: Religion, Politics, and Violence in Sri Lanka By Stanley Jeyaraja Tambiah, p. 152-3
- A SHORT HISTORY OF LANKA by Humphry William Codrington, CHAPTER I; THE BEGINNINGS 'The princess and her retinue/dowry (service castes)'
- 'Pandyan retinue of Prince Vijaya': Sea: Our Saviour By K. Sridharan, p.19
- Pre-Vijayan Agriculture in Sri Lanka, by Prof. T. W. Wikramanayake
- Kshatriya, GK (December 1995). "Genetic affinities of Sri Lankan populations". Hum. Biol. 67 (6): 843–66. PMID 8543296.
- Mitochondrial DNA history of Sri Lankan ethnic people: their relations within the island and with the Indian subcontinental populations, L Ranaweera, et al; Journal of Human Genetics (2014)
- Nilaperumal Kalukapuge aka Badaranayaka
- J.R. Jayawardena family History of the Colombo Chetties, edited and compiled by Deshabandu Reggie Candappa, Reviewed by Anne Abayasekara (Sunday Times, 08.07.2001)
- Pilimatalavuva - Family, roots.web, Accessed 13-06-2015
- "How it Came to This – Learning from Sri Lanka's Civil Wars By Professor John Richardson" (PDF). paradisepoisoned.com. Retrieved 2006-03-30.
- "Ethnic Identity, National Identity and the Search for Unity" (PDF). World Council of Churches. Retrieved 2006-03-30.
- "Significance of the abortive 1962 military coup". Hindustan Times. Retrieved 2006-03-30.
- "The Human Rights and Humanitarian Fallout from the Sri Lankan Government's Eastern Agenda and the LTTE's Obduracy". UTHR. Retrieved 2006-03-30.
- "TamilNet: 23.04.13 Indian news magazine highlights accelerated Sinhalization of Tamil north". UTHR. Retrieved 2013-04-23.
- "Exclusive: Erasing the cultural leftover of Tamils to convert Sri Lanka into Sinhala country". UTHR. Retrieved 2013-04-23.
- "New military colonies in Murukandi; Sinhalization in Puthumathalan". UTHR. Retrieved 2013-04-23.
- "Salt on Old Wounds: The systematic Sinhalization of Sri Lanka's North, East, the historic habitat of the Tamil speaking people". UTHR. Retrieved 2013-04-23.
- Pilimatalavuva Family by Ananda Pilimatalavuva, 05-08-2019