Aer Lingus recorded an operating profit of €305m last year, its parent company International Consolidated Airlines Group (IAG) has revealed.
This was a record performance for the Irish flag carrier and an improvement of €37m over the last year.
The IAG annual report also showed that capacity increased 10% from additional flying to new routes - such as Philadelphia and Seattle.
However, despite a significant increase in capacity Aer Lingus' adjusted operating margin rose 0.6 points to 16.8%.
Passenger unit revenues decreased at outturn rates from lower yields, while non-fuel unit costs improved.
"Aer Lingus achieved significant cost savings through efficient growth with higher productivity and from cost initiatives. This included areas such as procurement and handling", IAG said.
In 2018, the IAG said its European markets continued to perform "strongly" with increases at Aer Lingus, British Airways and Spanish carrier Vueling.
North American capacity was also increased in British Airways, Iberia, and Aer Lingus.
"Aer Lingus' North American capacity was increased with the launch of new routes to Philadelphia and Seattle and the full year impact of routes launched in 2017", the report said.
The group carried almost 113 million passengers - an increase of 7.7% from 2017 - with passenger load factor improvement of 0.7 points for the group and at four of the five airlines.
However it said air-traffic control disruption impacted on Spain's Vueling, resulting in both the carrier and the group missing its 2018 NPS target of 20.
Iberia's 2018 score was broadly flat versus its target, while British Airways and Aer Lingus exceeded their 2018 targets.