Lacertilia was named by Owen (1842). It is extant. It was considered monophyletic by Prothero and Estes (1980).

It was reranked as the order Lacertilia by Owen (1861), Osborn (1903), Miller (1967), Seiffert (1975), Carroll and Galton (1977), Thurmond and Jones (1981), Carroll (1982), Sullivan (1986), Carroll (1988) and Peng et al. (2001); it was synonymized subjectively with Sauria by Sulimski (1975) and Lingham-Soliar (1994); it was synonymized subjectively with Sauria by Dundee (1989); it was reranked as the unranked clade Lacertilia by Augé and Rage (2006); it was reranked as the suborder Lacertilia by Prothero and Estes (1980), Estes (1983), Gao and Fox (1991), Gao and Fox (1996), Gao and Hou (1996), Venczel and Stiuca (2008) and Böhme (2010).

It was assigned to Reptilia by Owen (1861); to Squamata by Miller (1967); to Sauria by Estes (1983); to Sauria by Sullivan (1986); to Reptilia by Augé and Rage (2006); and to Squamata by Osborn (1903), Seiffert (1975), Carroll and Galton (1977), Prothero and Estes (1980), Thurmond and Jones (1981), Carroll (1982), Carroll (1988), Gao and Fox (1991), Gao and Fox (1996), Gao and Hou (1996), Peng et al. (2001), Venczel and Stiuca (2008) and Böhme (2010).