Rajputisation (or Rajputization) explains the process by which a diverse mix of various different social groups (castes) and different varnas coalesced to form the Northern Indian Rajput community.

According to modern scholars, almost all Rajputs clans originated from peasant or pastoral communities. Rajputisation is the study of formation of the community over the centuries.

Sivaji Koyal suggests that Rajputisation boosted Brahmanism and defines it as follows,

It is the means whereby a tribal chief establishes the pretensions to being a kshatriya, and surrounds himself with the paraphernalia of Brahmanism for the purpose of securing prestige.

Sociologists like Sarah Farris and Reinhard Bendix state that the original Kshatriyas in the northwest who existed until Mauryan times in tiny kingdoms were an extremely cultured, educated and intellectual group who were a challenge to monopoly of the Brahmins. According to Max Weber, ancient texts show they were not subordinate to the Brahmins in religious matters. These old Kshatriyas were undermined not only by the Brahmin priests of the time but were replaced by the rise of the new community of illiterate mercenaries in the north-west - the Rajputs. Since the Rajputs were generally illiterate unlike the Kshatriyas, their rise did not present a challenge to monopoly of the Brahmins.

Anyone from the "village landlord" to the "newly wealthy lower caste Shudra" could employ Brahmins to retrospectively fabricate a genealogy and within a couple of generations they would gain acceptance as Hindu Rajputs. This process would get mirrored by communities in north India. Scholars refer to this as "Rajputisation" and consider it similar to Sanskritisation. This process of generation of the Rajput community resulted in hypergamy as well as female infanticide that was common in Hindu Rajput clans. German historian Hermann Kulke has coined the term "Secondary Rajputisation" for describing the process of members of a tribe trying to re-associate themselves with their former tribal chiefs who had already transformed themselves into Rajputs via Rajputisation and thus claim to be Rajputs themselves.

Stewart N. Gordon states that during the era of the Mughal empire, "Hypergamous marriage" with the combination of service in the state army was another way a tribal family could convert to Rajput. This process required a change in tradition, dressing, ending widow remarriage, etc. Such marriage of a tribal family with an acknowledged but possibly poor Rajput family would ultimately enable the non-Rajput family to become Rajput. This marriage pattern also supports the fact that Rajput was an "open caste category" available to those who served in the state army and could translate this service into grants and power at the local level.

Scholars also give some examples of entire communities of Shudra origin "becoming" Rajput even as late as the 20th century. William Rowe, in his "The new Chauhans : A caste mobility movement in North India", discusses an example of a large section of a Shudra caste – the Noniyas – from Madhya Pradesh, Uttar Pradesh and Bihar that had "become" Chauhan Rajputs over three generations in the Raj era. The more wealthy or advanced Noniyas started by forming the Sri Rajput Pacharni Sabha (Rajput Advancement Society) in 1898 and emulating the Rajput lifestyle. They also started the wearing of sacred thread. Rowe states that at a historic meeting of the caste in 1936, every child this Noniya section knew about their Rajput heritage.