Yes. Both the grounds and the first floor of the castle are available for event rentals. There is a 50 person occupancy limit for all indoor rentals. Rental rates are set by ordinance and can be downloaded at the Permits, Fees, Rentals link.
The first floor of Kip's Castle is open to the public for self-guided tours Tuesday through Friday from 12:00pm to 3:00pm from May 1st - October 31st. The second and third floors are not accessible at this time.
The grounds at Kip's Castle Park are open from dawn to dusk seven days a week.