The Twitter CEO is investing $1 billion of his estimated $3.9 billion worth, according Bloomberg's Billionaires Index.
The money will come from his mobile payments company Square and the aim is to help support UBI (Universal Basic Income), girl's health and education.
Dorsey said: "I've discovered and funded ($40m) many orgs and proven impact and efficiency in the past, mostly anonymously.
"Going forward, all grants will be public. Suggestions welcome.
He continued on the micro-blogging site: "I'll need to pace the sales over some time.
"The impact this money will have should benefit both companies over the long term because it's helping the people we want to serve."
He added: "Why UBI and girl's health and education?
"I believe they represent the best long-term solutions to the existential problems facing the world.
"UBI is a great idea needing experimentation. Girl's health and education is critical to balance.
"Why now? The needs are increasingly urgent and I want to see the impact in my lifetime.
"I hope this inspires others to do something similar. Life is too short, so let's do everything we can today to help people now."