Expired yogurt is fine to eat as long as it is consumed within a certain amount of time. For example, unopened regular yogurt can be consumed two to three weeks past its sell-by date.
Other types of yogurt, such as Greek yogurt or reduced-fat yogurt, are safe to consume one to two weeks after the sell-by date as long as the yogurt is unopened. Yogurt with fruit is generally safe to consume seven to 10 days past its sell-by date. Yogurt that has been opened should be consumed within a week after opening. If yogurt has mold or is overly watery, it should be discarded immediately.