The Census and Statistics Department said the increase compared with a 4.2 percent growth in the second quarter. On a seasonally adjusted basis, GDP rose 1.9 percent quarter on quarter.
For the first nine months combined, the economy grew 5.1 percent – the fastest growth for the period in five years.
Goods exports rose 30.4 percent in real terms, after 28.9 percent in the second quarter, while imports grew 29.9 percent.
Exports of services increased 4.3 percent. Investment strengthened, with gross domestic fixed capital formation up 7.3 percent, while private consumption grew 2.8 percent and government consumption was up 1.7 percent.
A government spokesman said the economy saw robust expansion, underpinned by accelerating exports and solid domestic demand.
He said the outlook remained positive, citing global artificial intelligence investment, inbound tourism, cross-boundary traffic and financial market activity.
But he advised caution over geopolitical tensions in the Middle East and tighter monetary policies by major central banks.
Revised GDP figures and the updated forecast for 2026 will be released on November 13.
Separately, retail sales rose 6.4 percent year on year in September to a provisional HK$33.4 billion – the 17th straight month of expansion.
August’s revised increase was 5.6 percent, and sales for the first nine months were up 8.3 percent by value.
Online sales rose 12 percent to HK$4.4 billion in September, or 13.1 percent of total retail sales, and were up 21.2 percent for the first nine months.
Retail sales volume rose 3.9 percent in September.
The spokesman said solid local consumption sentiment, more visitor arrivals and earlier Mid-Autumn festive sales supported retail growth.
He said upcoming mega events, festive celebrations and inbound tourism should add momentum, though external headwinds warranted close monitoring.