Do SQL Server stored procedures cache data results?
Query results are not cached

However, the source table and index data and metadata will be cached after the 1st use (subject to continued use, load and memory pressure though)

That is, the results of a query will be evaluated every execution but the tables(s) (and any indexes etc) used by the query will most likely be in memory already.

The compiled execution plan will be cached which is where the confusion comes from I suspect