In a CNBC article Jon Ossoff said he is in favor of nationwide legalization of cannabis. 

"I won’t just push for decriminalization; I’ll push for nationwide legalization of cannabis. The prohibition of this substance is irrational. It’s hugely expensive. It has a terrible human toll.

The fact that there are people doing time for nonviolent marijuana-related offenses while others are getting rich in the cannabis industry is a grave injustice. I’ll fight for outright cannabis legalization, an end to incarceration for nonviolent drug offenses and expungement of records for nonviolent cannabis offenses" (July 16, 2020)