Lanthanide-based perovskites have been widely studied as catalysts for carbon monoxide oxidation. In particular, there has been a special interest in the influence of manganese, cobalt and iron as M-cations. Cobalt-based materials seem to exhibit the most promising activities but cobalt is considered a critical raw element by the EU. Although iron catalysts seem to exhibit poor activity in comparison to other metals, the high availability and low cost of iron precursors have kept lanthanide ferrite materials in the scientific spotlight.