The figures come amid a renewed weakness for sterling, which traded at 91.25p, the second-lowest level since the Brexit referendum last summer.
In recent days, major international banks have predicted sterling could drop much further and reach a historic low of parity against the euro, because the eurozone economy is expanding at a time when the UK economy is slowing.
CSO figures show exports across the Irish Sea rose to almost €7.2bn for the first six months, an increase of 14% from a year earlier.
Imports from Britain rose 7% to almost €8.2bn.
The figures may be evidence that Irish firms have weathered the first waves of the Brexit fallout better than many expected.
There had been fears that the 15% slump in the value of sterling against the euro since the eve of the referendum would significantly hamper Irish exporters because the currency drop means firms make a good deal less on the sales they make into Britain.
The CSO figures suggest that indigenous Irish firms, such as food companies, which tend to be more exposed than multinationals to sudden foreign currency changes, increased the value of their overall goods exports over the first six months of the year.
All but two of 10 types of food exports posted gains, with food exports across the world, and not just to Britain, climbing by 5% to €3.42bn from a year earlier.
However, at €396m, exports of beverages were 9% lower.
Meanwhile, industries dominated by the multinationals fared even better.
The value of exports of medical and pharmaceutical products across the world surged 73% to almost €4.88bn in the first six months of the year, according to the CSO figures.
In June alone, medical and pharmaceutical products rose 14% from the same month in 2016, although exports of organic chemicals were down 24%.
Volatile exports of machinery and transport, which can be affected by just a handful of the enormous air leasing giants based in Ireland, were down sharply, by 15% to €13.23bn, over the first six months compared with a year earlier.