When was the last stock split?

Shareowners of record as of July 27, 2012 were entitled to a two-for-one stock split payable August 10, 2012. Shareowners of record were sent notification of the shares received as a result of the split.

View stock split summary here.

https://www.coca-colacompany.com/content/dam/journey/us/en/our-company/shareowner-services/history-of-stock-splits.pdf