They were arrested under a national security law on suspicion of collusion with a foreign country to endanger national security, according to reports.
Local media, including the South China Morning Post and Apple Daily, reported national security police arrested paper’s chief editor Ryan Law.
Police entered the Apple Daily office premises at around 07:30 local time on Thursday (11.30 UK time) and blocked entrances and exits.
The paper broadcasted live footage of the raid on its Facebook account.
Others arrested included Cheung Kim-hung, the CEO of Next Digital, which operates Apple Daily.
Its chief operating officer and two other editors were also detained for "suspected contravention" of the territory's controversial national security law.
Apple Daily is known to be critical of Beijing's leadership. It is owned by media mogul Jimmy Lai, who was also arrested and jailed on a string of charges.
Dozens of prominent activists have been arrested since the national security law was introduced in 2020.
Police said in a statement that they conducted a search operation at a media company, adding that the warrant "covered the power of searching and seizure of journalistic materials”.
They did not name those arrested but confirmed that the five people, aged between 47 and 63, were arrested for "collusion with a foreign country or with external elements to endanger national security”.