As of my knowledge cutoff in 2021, the following countries have legalized the use of cannabis:
Canada
Uruguay
South Africa
Georgia (for personal use only)
Portugal (decriminalized, not fully legalized)
Netherlands (decriminalized, not fully legalized)
Spain (for personal use only)
several states and territories in the US such as California, Colorado, Alaska, and Washington D.C. also have legalized marijuana usage.
It's important to note that laws and regulations surrounding cannabis are constantly changing and evolving, and this list may not be exhaustive or entirely up to date.