We generalize the Mahowald invariant to the R-motivic and C2-equivariant settings. For all i > 0 with i ≡ 2, 3 mod 4, we show that the R-motivic Mahowald invariant of (2 + ρη) i ∈ π R 0,0 (S 0,0) contains a lift of a certain element in Adams' classical v1-periodic families, and for all i > 0, we show that the R-motivic Mahowald invariant of η i ∈ π R i,i (S 0,0) contains a lift of a certain element in Andrews' C-motivic w1-periodic families. We prove analogous results about the C2-equivariant Mahowald invariants of (2 + ρη) i ∈ π C 2 0,0 (S 0,0) and η i ∈ π C 2 i,i (S 0,0) by leveraging connections between the classical, motivic, and equivariant stable homotopy categories. The infinite families we construct are some of the first periodic families of their kind studied in the R-motivic and C2-equivariant settings. Contents −N