In the My Hero Academia movie "world heroes mission", the police officer from a foreign country calls Endeavor "the number one hero in Japan". Does this mean all the rank list we knew for heroes was only for Japan? And also All Might was never the number one hero of the world?
Is Endeavor the number one hero only in Japan or this is just a non canon invention from the movie?
Your analysis is correct.
With the question Aki linked, Why do the top 10 heroes in Boku no Hero Academia only come from Japan?, it is shown canonically that the ranking board mentioned throughout the anime and movies refers to the local Japanese hero rank. So yes, Endeavor is currently the number one hero of Japan; with All Might being the former number one hero of Japan
To further support this in the manga:
Cathleen Bate was revealed to be the number one hero of the USA in chapter 328
