A search for pair-produced scalar electron, muon and tau leptons has been performed using a data sample corresponding to an integrated luminosity of 10.1 pb-1 at a centre-of-mass energy of √s = 161 GeV collected with the OPAL detector at LEP. Such events would yield an acoplanar pair of leptons with significant missing energy in the final state. No excess of acoplanar lepton pair events has been observed in the data. Limits are presented on the production cross-sections of charged scalar leptons. Exclusion regions are also presented in the framework of the Minimal Supersymmetric Standard Model. A 95% C.L. lower limit on the right-handed selectron mass of 71.5 GeV is obtained for tan β >= 1.5, μ >= 200 GeV andmχ~01 = 12.0 GeV. A 95% C.L. lower limit on the right-handed smuon mass of 51.0 GeV is obtained formχ~01 = 12.0 GeV, independent of tan β and μ.