Yogurt does have some lactose, but it is less lactose than milk because yogurt manufacturers strain the yogurt, removing some of the lactose. Greek yogurt has up to 95 percent of its lactose removed, leaving between 2 and 6 grams of lactose per 6-ounce serving.
Regular yogurt has more lactose than Greek yogurt but less lactose than milk. Regular yogurt contains about 11 grams of yogurt per 6-ounce serving. The difference in lactose comes from the amount of whey removed from the yogurt. Thicker yogurts have less whey and less lactose. The live cultures contained in yogurt may temper the effect of lactose on lactose-intolerant people.