Peel the papaya, halve and scoop out seeds. Dice into 1” cubes. Slice the avocado lengthwise, pit and scoop out the flesh. Cut into 1” cubes. Peel and section the grapefruit, reserve t tablespoons juice for the dressing.
Place grapefruit, papaya, avocado and mint leaves in a bowl. In a small bowl, stir together yogurt, grapefruit juice and honey. Pour dressing over the fruit and carefully toss.