Anoplosaurus was named by Seeley (1879). It was considered monophyletic by Vickaryous et al. (2004).

It was synonymized subjectively with Acanthopholis by Nopcsa (1902) and Nopcsa (1915); it was considered a nomen dubium by Brinkmann (1988); it was considered a nomen dubium by Norman and Weishampel (1990).

It was assigned to Dinosauria by Seeley (1879); to Scelidosauria by Sauvage (1882); to Scelidosauridae by Sauvage (1882) and Zittel (1890); to Omosauridae by Huene (1909); to Stegosauridae by Nopcsa (1901) and von Zittel (1911); to Acanthopholidae by Huene (1927); to Camptosauridae by Stromer (1934); to Iguanodontidae by Swinton (1936), Romer (1956), Tatarinov (1964), Kuhn (1964), Romer (1966), Thulborn (1974), Buffetaut et al. (1981), Weishampel and Weishampel (1983) and Carroll (1988); to Ankylosauria by Vickaryous et al. (2004); to Struthiosaurinae by Kirkland et al. (2013); and to Nodosauridae by Hennig (1915), Pereda Suberbiola and Barrett (1999), Ford (2000), Carpenter (2001), Pereda Suberbiola and Galton (2001), Naish and Martill (2007), Naish and Martill (2008), Blows and Honeysett (2014), Blows (2014) and Yang et al. (2017).