  We present global spectral energy distributions (SEDs) from 0.3$\mu$m to 90cm
for a sample of seven low-metallicity blue compact dwarf galaxies (BCDs). In
addition to data compiled from the literature, we report new SCUBA data for the
galaxies in the sample, including the two most metal-poor star-forming galaxies
known, IZw18 and SBS0335-052. The standard starburst templates, M82 and Arp220,
do not give a good approximation to any of the BCD SEDs in our sample. Several
SEDs are instead characterized by: (i) approximately flat radio spectra
suggesting dominant thermal processes; (ii) far-infrared (FIR) spectra which
peak at or shortward of 60 $\mu$m; (iii) a significant warm dust component and
absence of Aromatic Features in Emission (or PAHs) in the mid-infrared (MIR).
The SEDs of low-metallicity BCDs do not follow ``canonical'' scaling relations,
and the ``standard'' star-formation indicators based on radio continuum, FIR,
and MIR luminosities can be discrepant by factors of $\simgt10$. We present new
models of the dust SEDs from 5$\mu$m to 1cm, and derive infrared luminosities,
dust distributions, temperatures, and masses. The observed SEDs and dust models
are interpreted in terms of the active/passive regimes of star formation and
trends with metallicity. Finally, we discuss the implications of our results on
the $z\simgt6$ starburst populations which will be detected by forthcoming
submm and radio facilities.
