The announcement comes despite the firm struggling to recover its reputation for safety after the recall of millions of cars around the world for various problems.
The firm said it shifted 10.13 million units in the 12 months to the end of March, a rise of 4.5 percent year on year and likely setting an industry record.
Its closest rivals, Germany's Volkswagen and US-based General Motors report their sales on a calendar-year basis but analysts said it was unlikely they had sold over 10 million vehicles in any 12-month period.
Toyota pointed to strong sales at home and in key overseas markets, including China, now the world's biggest vehicle market.
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Group sales in Japan rose 3.9 percent to a record 2.4 million units, the third consecutive fiscal year increase, Toyota said.
"Rush demand ahead of the consumption tax increase in April this year led to strong sales in Japan for us," a Toyota spokesman said in an e-mail.
Japan raised its national sales tax to 8.0 percent from 5.0 percent on April 1, the first levy hike since the late 1990s as Tokyo works to bring down one of the rich world's biggest debt burdens.
Two weeks ago, Toyota recalled 6.39 million vehicles globally over a string of problems, dealing another blow to the automaker whose reputation for quality and safety has been dented after a handful of earlier recalls numbering in the millions over the past few years.
In February, Toyota announced it was recalling 1.9 million of its signature Prius hybrid cars, after the discovery of problems with software used to control a power converter that posed a risk to drivers.
Rival GM has been sideswiped by accusations that it hid a decade-long ignition and airbag problem linked to 13 deaths.
Japanese rivals including Nissan and Honda have also issued major recalls in recent years.
Toyota shares slipped 0.16 percent to finish at 5,549 yen (USD 54) in Tokyo.