Techniques are provided for adaptive look-ahead configuration for data prefetching. One method comprises, in response to a request for a data item in a storage system: obtaining a size of a look-ahead window for the request based on one of multiple available caching policies; and moving the requested data item and additional data items within the look-ahead window to the cache memory when the requested data item and/or the additional data items within the look-ahead window are not in the cache memory. The multiple available caching policies comprise a caching policy based on characteristics of an input/output workload of the storage system, or a portion thereof; and/or a caching policy based on an input/output workload of at least a portion of the storage system within a prior predefined time window. The look-ahead window size may be varied over time.