“Suppressor T cells” were historically defined within the CD8⁺ T‐cell compartment and recent studies have highlighted several naturally occurring CD8⁺Foxp3⁻ Treg populations. However, the relevance of CD8⁺Foxp3⁺ T cells, which represent a minor population in both thymi and secondary lymphoid organs of nonmanipulated mice, remains unclear. We here demonstrate that de novo Foxp3 induction in peripheral CD8⁺Foxp3⁻ T cells is counter‐regulated by DC‐mediated co‐stimulation via CD80/CD86. CD8⁺Foxp3⁺ T cells fail to develop in TCR‐transgenic mice with Rag1^−/− background, similar to classical CD4⁺Foxp3⁺ Tregs. Notably, both naturally occurring and induced CD8⁺Foxp3⁺ T cells express bona fide Treg markers including CD25, GITR, CTLA4 and CD103, and show defective IFN‐γ production upon restimulation when compared with their CD8⁺Foxp3⁻ counterparts. However, utilizing DEREG transgenic mice for the isolation of Foxp3⁺ cells by eGFP reporter expression, we demonstrate that induced CD8⁺Foxp3⁺ T cells similar to activated CD8⁺Foxp3⁻ T cells only mildly suppress T‐cell proliferation and IFN‐γ production. We therefore categorize CD8⁺Foxp3⁺ T cells as a tightly controlled population sharing certain developmental and phenotypic properties with classical CD4⁺Foxp3⁺ Tregs, but lacking potent suppressive activity.