Dacnis viguieri is monotypic (Dickinson and Christidis 2014, Clements et al. 2015). Two males from eastern Panama and Colobia (Quimarí) have bluer sides to the head and nape, and are generally bluer overall, whereas specimens from Juradó have the sides of the head and nape greener (Meyer de Schauensee 1950, 1951).
Described as Dacnis viguieri by Salvin and Godman (1883) from the Isthmus of Panama, on the shores of the Gulf of Darien (Storer 1970).
The genera Dacnis and Cyanerpes formerly were placed in the nectar-feeding family Coerebidae (e.g., Sclater 1886, Hellmayr 1935); however, many of these species have been shown to have converged on a similar morphology due to nectar feeding. Early researchers noticed that some coerebids shared similar morphological features with tanagers, such as horny palates, and in the details of skull morphology, jaw musculature, and plumage (Beecher 1951, Tordoff 1954, Storer 1969). Molecular data has confirmed these early hypotheses, and Coerebidae has been largely rejected with Dacnis now placed in the Thraupidae (Isler and Isler 1987, Burns et al. 2003). More recently, the genus Dacnis has been classified in the subfamily Dacninae, which contains three genera, Dacnis, Cyanerpes, and Tersina. Dacnis forms a monophyletic sister clade to the clade containing Cyanerpes and Tersina (Burns et al. 2014). The close relationship between Cyanerpes and Dacnis long has been established, but the close relationship between these genera and Tersina was unexpected due to morphological differences of their beaks (Burns et al. 2003, Burns et al. 2014). Genetic data were unable to recover strong support for relationships among the species of Dacnis, and resolving these relationships should be the focus of future research (Burns et al. 2014).