The campaign, known as Operation Torus, ran from 5 September until 31 October.
During that time police carried out 674 searches and made 586 drugs seizures.
Three hundred and seventy-three people were arrested and of those, 279 were either charged or reported to the Public Prosecution Service.
Acting Det Ch Supt Andrea McMullan, from the PSNI's reactive and organised crime branch, described the operation as a "great success".
"In the eight weeks of the operation we have removed over £3.3 million worth of drugs from our streets," she said.
"Street-level drug dealing is happening across all districts throughout Northern Ireland, causing hurt and harm to communities.
"We as police will do everything that we can to tackle this issue, but we need to work in partnership with our local communities, and I encourage people to share any information, no matter how small, with us."
Drugs worth £3.36m have been seized by police as part of a campaign to tackle street-level drug dealing in Northern Ireland.