The company says net income totalled $174.6m (£111m) in the three months to 30 September, up from $165.6m in the same period last year as clients upped spending on advertising and promotions.
Worldwide revenue increased 5.5% to $2.9bn (£1.8bn) from $2.8bn (£1.7bn) with a strong showing in US, up 8.4% to $1.6bn (£1.01bn).
International revenue, which includes earnings from its UK agency operations, increased 2.3% to $1.3bn (£800m).
Omnicom, which also owns media agency networks OMD Worldwide and PHD, had seen profit and revenue suffer in the recession as clients cut back on marketing spend but has seen its fortunes improve this year.
The group’s performance matches improvements seen by other marketing services groups. Havas reported revenue increased by 12.6% in the latest quarter.
Recent studies by and Zenith Optimedia have also reported an upward trend in ad spend.