The fine was imposed by France's competition and fraud watchdog DGCCRF, which said consumers were not warned.
In 2017, Apple confirmed that it did slow down some iPhones, but said it only did so to "prolong the life" of the devices.
Apple said in a statement that it had resolved the issue with the watchdog.
The French watchdog said iPhone owners "were not informed that installing iOS updates (10.2.1 and 11.2) could slow down their devices".
As part of the agreement, Apple must display a notice on its French-language website for a month.
It says Apple "committed the crime of deceptive commercial practice by omission" and had agreed to pay the fine.
Yes. Since Apple confirmed the practice in 2017, it has implemented it on several more iPhones including:
iPhone 6, 6 Plus, 6S, 6S Plus
iPhone 7 and 7 Plus
iPhone 8 and 8 Plus running iOS 12.1 or higher
iPhone X running iOS 12.1 or higher
iPhone XS, XS Max and XR running iOS 13.1 or higher
The setting is only enabled when the battery begins to degrade, and iOS now offers clearer information to consumers about when performance management has been switched on.
"The effects of performance management on these newer models may be less noticeable due to their more advanced hardware and software design," Apple said.
Wonder what your customer really wants? Ask. Don’t tell.