The Government is to set up a new multi-agency base in the British capital, which will also house a re-located Irish embassy.
'Ireland House' will see the embassy and several agencies come together under one roof for the first time.
Bord Bia, Enterprise Ireland and IDA Ireland will be located on a single site in central London.
A lease for the new site is expected to be signed "following due diligence under the Public Spending Code," the Government has said.
The building - to be located near Whitehall, the Mall and Trafalgar Square - is expected to open in early 2026.
It is expected to be ready in early 2026 following a refurbishment and fit-out.
The Government has said the exact location will be confirmed "once commercially sensitive lease negotiations are complete."
Tánaiste Micheál Martin got Government approval for the plan, as part of its Global Ireland strategy, on Tuesday.
The Government launched Global Ireland in June 2018 with the aim of doubling the impact of Ireland's global footprint and influence out to 2025.
This includes through an expanded and strengthened diplomatic presence internationally.
London contains Ireland's largest bilateral presence in any city in the world.
The UK is also Ireland's largest export market - valued at €8.43bn in 2021 - representing 31% of total exports.
Britain accounted for 10% of the IDA's client portfolio in 2022, and is also the largest export market for Irish food and drink for Bord Bia and its clients.
Since 2018, Irish food and drink exports have increased by 19% to €5.3 billion.
There are already 21 'Ireland House' offices globally - this will be number 22.