In　this　work,　the　unsteady　magnetohydrodynamics　boundary　layer　flow　and　heat　transfer　of　novel　generalized　Kelvin-Voigt　viscoelastic　nanofluids　over　a　moving　plate　are　investigated.　The　classical　Kelvin-Voigt　constitutive　relation　is　generalized　to　incorporate　a　time-fractional　derivative　to　characterize　the　fluid　behavior,　which　is　proved　to　be　of　significance　and　physically　justified.　The　newly　developed　fractional　Kelvin-Voigt　constitutive　correlation　and　a　dual-phase-lagging　constitutive　equation　are　applied　to　the　momentum　and　energy　equations,　respectively,　for　a　nanofluid　model　over　a　moving　plate.　The　formulated　integrodifferential　velocity　and　thermal　boundary　layer　equations　are　solved　using　the　finite　difference　method　together　with　a　fast　algorithm,　which　reduces　the　consumed　central　processing　unit　time　significantly.　Several　numerical　examples　are　presented　to　illustrate　the　influence　of　the　critical　parameters　on　the　nanofluid　motion　and　thermal　characteristics.　Compared　to　the　fractional　Maxwell　nanofluid　model,　the　velocity　boundary　layer　for　the　fractional　Kelvin-Voigt　nanofluid　model　is　thinner.　Although　the　fractional　indexes　show　similar　effects　on　the　velocity　boundary　layer,　the　impacts　of　the　relaxation　parameters　are　in　contrast.　This　work　provides　valuable　insights　into　the　feasibility　of　using　the　fractional　Kelvin-Voigt　viscoelastic　model　to　depict　the　fluid　flow　and　heat　transfer　characteristics　of　nanofluids.　©　2024　Author(s).