Dentsu emerged as the leading media agency group in Ireland during the first half of 2026, as a relatively small number of major international account reviews had a significant impact on the Irish media agency market, according to new figures from the media research firm COMvergence.
The research firm’s latest New Business Barometer tracked 28 media account moves and pitches in Ireland during the six months, representing approximately €40.5m in media spend.
Of this, around €13.2m related to pitches originating in the Irish market while €27.3m was associated with regional or global pitches. Around €19.4m, or 49% of the total spend reviewed, related to accounts ultimately retained by incumbent agencies.
Dentsu topped the Irish agency group rankings with approximately €14.7m in total new business, including retentions. Its performance was largely driven by the Heineken account, valued by COMvergence at around €10.4m, and Netflix, worth approximately €4.8m.
WPP Media was second with around €5.5m, helped by business including Jaguar Land Rover, valued at approximately €2.1m, Just Eat at €1.7m and Demant Group at €1.4m.
Core and Omnicom Media followed with approximately €2.6m each, according to COMvergence.
However, the underlying figures also show significant differences between new client gains and retained business.
According to the COMvergence table, Dentsu’s Irish result included around €15.2m in retained business, leaving the group approximately €500,000 down on a net basis when retentions are excluded. WPP Media recorded approximately €2.9m in net new business excluding retentions, Omnicom Media around €2 million, and Core Group with approximately €700,000.
At individual agency level, Red Star headed the Irish rankings with approximately €10.4m followed by iProspect on €4.8m, Mindshare (WPP Media) on €4.5 million, PHD (Omnicom Media Group) on €2.6m and Spark Foundry Ireland (Core) on €1.9m.
The largest accounts reviewed during the period included Heineken at approximately €10.4m, Netflix at €4.8m, Allianz Health & Life at €2.8m and JLR and Adidas, each valued at around €2.1m.
The figures also underline the extent to which developments in the Irish media agency market are being determined by international rather than locally-run pitches.
While local pitches accounted for 58% of the media spend reviewed by COMvergence globally, they represented just 28% of the spend reviewed in Ireland during the first six months of 2026.
In the UK, meanwhile, WPP Media emerged as the leading media agency group during the first half of the year.
COMvergence tracked 88 account moves and pitches representing $1.1 bn (€967.6m) in media spend. Of this, $475m (€417.8m) related to local pitches and $658m (€578.8m) to regional or global reviews. Retained accounts accounted for $223m (€196.2m), or 20% of the spend reviewed.
The global picture was different again, with Publicis Media taking the top position among the five largest international media agency groups.
Publicis Media generated $3.24 bn (€2.85 bn) in total new business, including $903m (€794m) in retained billings.
Omnicom Media was second with $3.15bn (€2.77 bn), including $1.68 bn (€1.48 bn in new-client wins and $1.48 bn (€1.30 bn) in retentions.
WPP Media ranked third on $2.98 bn(€2.62 billion).
Dentsu and Havas Media Network, by contrast, finished the first half in negative territory, with Dentsu recording minus $181m (€159m) and Havas minus $343m (€302m) as losses outweighed wins and retentions.
COMvergence also identified a wider structural change in the international agency market, with increasing volumes of major advertiser business being consolidated within bespoke or centralised operations run directly by the large agency holding groups rather than being assigned solely to their traditional agency networks.
These centralised operations accounted for $5 bn (€4.40 bn), or 26%, of the $19.2 bn (€16.89 bn) in media spend reviewed globally during the first half.
Overall, COMvergence assessed 1,970 media account moves and retentions across 49 countries, involving 1,070 advertisers and $19.2 billion (€16.89 billion) in reviewed media spend during the first half of 2026, an increase of 9% on the same period in 2025.
Independent agencies captured $3 bn (€2.64 bn, representing 16% of total global spend reviewed.
Olivier Gauthier, founder and CEO COMvergence, commented:“What we are seeing is a clear shift towards the consolidation of media business within bespoke, centralized solutions operated directly by the Big 5 holding groups, outside their global agency brands. In H1 2026, these solutions secured 26%, or $5.0 bn, of the $19.2 bn in total reviewed media spend.
“WPP Media led this shift, assigning $2.24 bn, or 69% of its total new wins, to its standalone group unit. Publicis Media followed with $1.50 bn (47%), and Omnicom Media with $1.11 bn (34%). Our H1 2026 New Business Barometer confirms that this model is becoming an increasingly significant force in the media landscape,” Gauthier added.
