Online sales jumped 33.1%, making up 10.1% of total retail sales.
Retail sales in Hong Kong rose 7.9% year on year to $33.8b in May, according to the Census & Statistics Department.
After adjusting for price changes, the volume of total retail sales increased 4.8% from a year earlier.
Online sales reached $3.4b, accounting for 10.1% of total retail sales. The value of online sales was provisionally estimated at $3.4b, a 33.1% increase from a year earlier.
Amongst retail categories, sales of consumer goods not elsewhere classified recorded the largest gain, rising 14.8% year on year.
Other sectors posting increases included jewellery, watches, clocks and valuable gifts, up 25.8%; electrical goods and other consumer durable goods not elsewhere classified, up 13%; optical items, up 10.3%; commodities in department stores, up 9.2%; furniture and fixtures, up 4.6%; books, newspapers, stationery and gifts, up 4.5%; footwear and clothing accessories, up 4.7%; medicines and cosmetics, up 3.5%; clothing, up 3%; motor vehicles and parts, up 1.7%; and supermarket commodities, up 0.9%.
However, several sectors recorded declines. Sales of food, alcoholic drinks and tobacco edged down 0.3%, whilst fuels fell 12.2% and Chinese drugs and herbs dropped 9.5% compared with May last year.
The government said retail sales continued to record solid growth during the month, with most major retail categories registering year-on-year increases.
Looking ahead, the government said continued economic expansion, sustained growth in local labour earnings and a steady rise in inbound visitors are expected to provide further support for the retail sector in the coming months.