The discovery of strong magnetic fields on three isolated white dwarf
stars, G111-49, G183-35, and G256-7, is reported. Effective field stre
ngths of +6.8 +/- 0.5 MG (1 MG = 10(6) G) in G183-35, +4.9 +/- 0.5 MG
in G256-7, and approximately -220 MG in G111-49 were measured with the
aid of circular spectropolarimetry. These stars, none of which were e
ver part of previous magnetic field searches, were found as part of a
polarization survey of DC white dwarf stars in search of magnetic fiel
ds greater than 500 kG.