A 'hemp rebellion' protest is due to take place in College Green on Sunday, July 19.
Protesters will be gathering in the central square at noon as part of the "Seed the Future Campaign".
Claire, the organiser for the Bristol event, said they exist for educational purposes and said nationally more than three tons of hemp seeds had been distributed.
The organisers are encouraging participants to bring a hemp plant if they have grown one.
Seeds and pots of soil also will be provided so participants can "plant a seed of hope" at the protest.
It says on the event's leaflet: "Almost a century ago, Hemp was the main competitor to the fossil fuel, pharmaceutical, timber and cotton industries.
"This continues to be the case today and, with emerging technologies, hemp has become a major solution to the climate emergency, our health crisis and our economic dependency.
"A re-emergence of the hemp industry, here in the UK and around the globe, will create a radical shift towards a Green Industrial Revolution and the decriminalisation of all actions relating to this plant will bring freedom, health and happiness to people."
Similar protests will be taking place across the country including London, Brighton, Birmingham and Cardiff.
According to the UK Government website, a licence from the Home Office is needed to grow hemp in the UK.
The Government says cannabis is a Class B controlled drug listed in Schedule 1 of the Misuse of Drugs Regulations 2001 and in the Misuse of Drugs Designation Order 2015.
Those wanting to cultivate industrial hemp therefore need to apply for a controlled drugs domestic licence.
