An airfoil (30; 130) for a gas turbine engine, comprising: an airfoil body (33; 133) extending in a spanwise direction from an inner end to an outer end and extending in a chordwise direction from a leading edge to a trailing edge, the airfoil body (33; 133) having a pressure side and an opposed suction side; a platform located at the inner end and/or the outer end of the airfoil body (33; 133), the platform extending transversally to the airfoil body (33; 133); and a fillet (40; 50; 140) at a junction between the airfoil body (33; 133) and the platform, the fillet (40; 50; 140) having a radius distribution at a given chordwise location, the radius distribution of the fillet (40; 50; 140) varying from the platform to the airfoil body (33; 133) in the spanwise direction, the radius distribution defining: a local minimum radius (RO22; R13; R23; R32; R52; R62; R72; R82; R92; R112; R132; R142; R152; R173; R192; R222; R232; R242), the radius of the fillet (40; 50; 140) at the given chordwise location increasing from the local minimum radius along the spanwise direction toward both of the airfoil (30; 130) and the platform; and a local maximum radius (RO23; R12; R22; R33; R53; R63; R73; R83; R93; R103; R113; R123; R133; R143; R153; R162; R172; R182; R193; R233) offset from the local minimum radius along the spanwise direction, the radius decreasing from the local maximum radius along the spanwise direction toward both of the airfoil (30; 130) and the platform, characterised in that: the fillet (40; 50; 140) has a plurality of fillet sections (43a; 53a) distributed all around the airfoil body (33; 133); and a radius of the fillet (40; 50; 140) varies continuously from the platform to the airfoil body (33; 133). an airfoil body (33; 133) extending in a spanwise direction from an inner end to an outer end and extending in a chordwise direction from a leading edge to a trailing edge, the airfoil body (33; 133) having a pressure side and an opposed suction side; a platform located at the inner end and/or the outer end of the airfoil body (33; 133), the platform extending transversally to the airfoil body (33; 133); and a fillet (40; 50; 140) at a junction between the airfoil body (33; 133) and the platform, the fillet (40; 50; 140) having a radius distribution at a given chordwise location, the radius distribution of the fillet (40; 50; 140) varying from the platform to the airfoil body (33; 133) in the spanwise direction, the radius distribution defining: a local minimum radius (RO22; R13; R23; R32; R52; R62; R72; R82; R92; R112; R132; R142; R152; R173; R192; R222; R232; R242), the radius of the fillet (40; 50; 140) at the given chordwise location increasing from the local minimum radius along the spanwise direction toward both of the airfoil (30; 130) and the platform; and a local maximum radius (RO23; R12; R22; R33; R53; R63; R73; R83; R93; R103; R113; R123; R133; R143; R153; R162; R172; R182; R193; R233) offset from the local minimum radius along the spanwise direction, the radius decreasing from the local maximum radius along the spanwise direction toward both of the airfoil (30; 130) and the platform, characterised in that: the fillet (40; 50; 140) has a plurality of fillet sections (43a; 53a) distributed all around the airfoil body (33; 133); and a radius of the fillet (40; 50; 140) varies continuously from the platform to the airfoil body (33; 133). a local minimum radius (RO22; R13; R23; R32; R52; R62; R72; R82; R92; R112; R132; R142; R152; R173; R192; R222; R232; R242), the radius of the fillet (40; 50; 140) at the given chordwise location increasing from the local minimum radius along the spanwise direction toward both of the airfoil (30; 130) and the platform; and a local maximum radius (RO23; R12; R22; R33; R53; R63; R73; R83; R93; R103; R113; R123; R133; R143; R153; R162; R172; R182; R193; R233) offset from the local minimum radius along the spanwise direction, the radius decreasing from the local maximum radius along the spanwise direction toward both of the airfoil (30; 130) and the platform, characterised in that: the fillet (40; 50; 140) has a plurality of fillet sections (43a; 53a) distributed all around the airfoil body (33; 133); and a radius of the fillet (40; 50; 140) varies continuously from the platform to the airfoil body (33; 133). the fillet (40; 50; 140) has a plurality of fillet sections (43a; 53a) distributed all around the airfoil body (33; 133); and a radius of the fillet (40; 50; 140) varies continuously from the platform to the airfoil body (33; 133).