<p>We investigated the effect of the Ni content on the face-centered cubic (FCC) phase stability and recovery strain of non-equiatomic CrMnFeCoNi alloys. From a well-known equiatomic CrMnFeCoNi high-entropy alloy, a series of Cr₂₀Mn₂₀Fe₂₀Co_{40−<i>x</i>}Ni_<i>x</i> alloys (<i>x</i> = 0, 2, 4, 6, 8 at.%) are designed, and their shape memory effect is discussed. The alloys with moderate Ni content (6 ≤ <i>x</i> ≤ 8 at.%) are the FCC single-phase solid solutions, whereas the alloys with a less Ni (<i>x</i> ≤ 4 at.%) display a FCC + hexagonal close-packed (HCP) dual-phase structure due to thermally induced martensitic transformation. The replacement of Ni with Co strongly increased <i>M</i>_s and <i>A</i>_s of the Ni-lean CrMnFeCoNi alloys (<i>x</i> ≤ 6 at.%) by 31&#xa0;K/at.% and 24&#xa0;K/at.%, respectively. The pre-strained single-phase Cr₂₀Mn₂₀Fe₂₀Co₃₄Ni₆ alloy (<i>x</i> = 6 at.%) exhibited the highest recovery strain of 1.2% in the Cr₂₀Mn₂₀Fe₂₀Co_{40−<i>x</i>}Ni_<i>x</i> system. This is attributed to the formation of stress-induced HCP martensite in a single orientation and low strain hardening compared with other dual-phase alloys. These results provide guidelines for designing new shape memory alloys in the CrMnFeCoNi and its derivative systems.</p>