A simultaneous decision by fellow holdout Hungary to schedule a Finnish ratification vote for March 27 means the US-led defence alliance will likely grow to 31 nations within a few months.
NATO's expansion into a country with a 1,340-kilometre (830-mile) border with Russia will roughly double the length of the bloc's current frontier with its Cold War-era foe.
Finland had initially aimed to join together with fellow NATO aspirant Sweden -- a Nordic power facing a litany of disputes with Turkey that ultimately sunk its chance to join the bloc before an alliance summit in July.
Helsinki and Stockholm ended decades of military non-alignment and decided to join the world's most powerful defence alliance in the wake of Russia's invasion of Ukraine.
Their applications were accepted at a June NATO summit that signalled the Western world's desire to stand up to Russia in the face of Europe's gravest conflict since World War II.
But the bids still needed to be ratified by all 30 of the alliance members' parliaments -- a process that got hung up once it reached Turkey and Hungary.
Friday's breakthrough followed months of tense negotiations between Ankara and the Nordic neighbours that threatened to collapse several times.
Erdogan told Finnish President Sauli Niinisto that Helsinki had shown a strong commitment to addressing Ankara's security concerns.
"We decided to start the protocol of Finland's accession to NATO in our parliament," Erdogan told reporters after the talks.
Erdogan added that he "hoped" that parliament will approve the application before Turkey's crucial general election in May.
The Turkish parliament is expected to end its current session in mid-April.