Panopeus was named by Milne Edwards (1834) [Sepkoski's age data: T Dani R]. It is extant. It is the type genus of Panopeidae, Panopeinae.

It was corrected as Panopaeus by Dana (1851); it was misspelled as Panopaeus by Bittner (1875), Rathbun (1918), Rathbun (1935), Glaessner (1980), Quayle and Collins (1981), Muller and Collins (1991), Schweitzer and Feldmann (2002), Sepkoski (2002), Casadio et al. (2005), Schweitzer et al. (2010), Beschin et al. (2013), Beschin et al. (2016), Luque et al. (2017), Beschin et al. (2018) and Schweitzer et al. (2021).

It was assigned to Xanthinae by Dana (1851); to Xanthidae by Bittner (1875), Rathbun (1918), Rathbun (1935), Quayle and Collins (1981) and Muller and Collins (1991); to Decapoda by Sepkoski (2002); to Panopeidae by Glaessner (1980), Schweitzer and Feldmann (2002), Casadio et al. (2005), Beschin et al. (2016) and Beschin et al. (2018); and to Panopeinae by Schweitzer et al. (2010), Beschin et al. (2013), Luque et al. (2017) and Schweitzer et al. (2021).