In October 2024, the nation's foreign workforce stood at 2.3 million -- an increase of around 254,000 people from a year earlier, labor ministry data showed.
That marks the biggest jump since records began in 2008, and is the latest in a series of annual record-breaking increases.
The total has jumped around threefold from a decade ago, in 2014, when the number of foreign workers stood at 788,000.
Japan has the world's second-oldest population after Monaco, according to the World Bank, and its relatively strict immigration rules mean it faces growing labor shortages.
Friday's data showed that Vietnamese, Chinese and Filipinos were the top three nationalities in Japan's foreign labor force.
Among the most common jobs held by foreign workers were positions in the manufacturing, hospitality, and retail sectors.
A "technical intern" program continued to account for a sizable portion of the foreign workforce, at 20.4%.
The state-sponsored scheme is ostensibly an attempt by Japan to give participants from countries such as China and Vietnam specialized experience to use in their home countries.
But critics have long called it a "backdoor" source of foreign labor in a conservative nation loath to officially acknowledge it is open to immigrants.
The intern program has also been long dogged by allegations of discrimination and physical abuse.