Legalising cannabis and scrapping prison sentences for personal use of drugs are among a range of pledges in the Liberal Democrat manifesto.
The party says plans to create a legal market for the production and sale of the class B drug would generate £1 billion in revenue and would "break the grip of the criminal gangs and protect young people".
Key pledges also include plans to decriminalise prostitution, which would allow police to dedicate more time to curbing people trafficking and grooming.
The wide-ranging document offers a number of promises to end discrimination, stating: "The rise in hate crime, the abuse of refugees, and the toxic rhetoric on immigration and about immigrants themselves is not the future Liberal Democrats want for Britain.
"We will not let campaigners for a hard Brexit pretend that racism and discrimination are a kind of patriotism."
Vowing to retain the Human Rights Act and strengthen punishments for hate crime, the party also promised to allow 50,000 more Syrian refugees into Britain and to reopen the Dubs scheme for unaccompanied child refugees.
The Lib Dems would spend £300 million to bolster local policing and require all police officers to wear body cameras to protect them and the public from abuses of power.
In the courts, the party pledged to clamp down on short prison sentences in favour of tough, non-custodial sentences, and to strengthen rights for victims.
The Lib Dems would also ensure transgender people are placed in prisons that reflect their gender identity, while allowing passports and official documents to include an X option for non-binary people.
Other measures include offering free sanitary products to schoolgirls and reviewing rules preventing gay men from donating blood.