The answer to your question is yes! There adapters available that will convert a standard 5.25 drive bay or a stabndard 3.5 drive bay to a 2.5 drive bay. The cost is anywhere from $2.99 to about $12.99 in the USA. It is not necessary to purchase the most expensive drive bay adapter.
Here are links to an examples of a 3.5 inch to 2.5 inch bay adapter: