Although the Audemars Piguet Royal Oak dates to 1972, it was not until 1998 that the company released a chronograph model. That first version, Ref. 25860, measured 39mm and was fitted with the ultra-thin Cal. 2385. This same calibre is used in all Royal Oak chronograph watches to date, and is based on an F. Piguet movement, Cal. 1185, that is also used in the Vacheron Constantin Overseas Chronograph and Breguet Marine Chronograph.
The company redesigned the Royal Oak Chronograph case in 2008 for Ref. 26300 with screws that extend through the case like the Offshore. One of the only visible differences is contrasting paint on the tips of the subdial hands for some models and a new “AP” logo single-deployant clasp instead of the simple box style. The similar Ref. 26022 was also introduced at this time. This 39 mm model was retired in 2012 and replaced by a larger 41 mm line.
The model line was refreshed in 2012 with a new 41 mm case. Although the movement is the same, many details are updated, including the signature “grande tapisserie” dial texture and the addition of a “butterfly” clasp with buttons. The larger 41 mm Ref. 26320 was now the standard Royal Oak Chronograph model. The "Leo Messi" Ref. 26325 was also introduced, with a tantalum bezel but without the tapisserie dial, in steel, gold, or a platinum Limited Edition.
The Royal Oak Chronograph was again refreshed in 2017 at SIHH with larger hour and minute chronograph subdials and a reduced small seconds subdial. Other changes include shorter and wider hour markers with more lume, and a new typeface on the subdials. The reference number was updated to Ref. 26331 at this time.
The following Royal Oak Chronograph models have been produced