Lycoming applied for certification of the O-233 on 13 June 1940, with certification to CAR 13 (amended to 31 May 1938) granted on 16 August 1940. The O-233 had its type certificate cancelled on 25 February 1944 at serial number 106.
The FAA type certificate notes:
No engines of these models manufactured after the date or with serial numbers above those listed below are eligible for use in certificated aircraft. (The early production engines may still be used in certificated aircraft or installed under a supplemental type certificate). Detail specifications for these engines have been deleted from this data sheet.