The sale was for more than 100 million Swiss francs ($102 million), the finnews.ch financial website reported on Monday.
A spokesman for Switzerland's second-biggest bank confirmed the sale but gave no financial details other than to say it would be booked in the third quarter as a sale-and-leaseback transaction.
He gave no reason for the sale. Swiss Prime Anlagestiftung, managed by Swiss Prime Site , also confirmed the transaction.
Credit Suisse, which made a second-quarter profit of 170 million francs, is in the midst of a revamp under Chief Executive Tidjane Thiam to focus more on wealth management and cut back on investment banking.
It has dismissed market speculation it may need fresh equity after a 6 billion franc capital raising round last year and plans to float part of its Swiss business, which the bank hopes will raise 2 billion to 4 billion francs.
The Leuenhof property -- once headquarters of Bank Leu, which was absorbed into Credit Suisse in 2012 -- now houses offices, luxury shops and a cafe.