There are a few different scenarios where the Singleton design pattern can be useful in Java. One common use case is when you need to ensure that only one instance of a given class is created. This might be important, for example, if you're working with a resource that can only be used by one object at a time. Another scenario where Singleton can be handy is when you want to make sure that all instances of a particular class share the same state. In this case, using a Singleton ensures that any changes to the state will be reflected across all objects. Finally, another advantage of the Singleton pattern is that it can help to improve performance by avoiding the need to create multiple instances of an object. In general, then, the Singleton design pattern can be a helpful tool in a number of different situations. If you need to make sure that only one instance of a class is created, or if you want to ensure that all objects share the same state, then using a Singleton may be the right choice. Additionally, the performance advantages of avoiding multiple object instantiations can also make this pattern worthwhile in some cases.