The airline will increase frequency on the route from three-times daily to five-times daily at its peak.
Between 26 May and 22 June, the service will increase to four-times daily.
Etihad will then add a fifth daily flight between 23 June and 28 September.
This will revert to four-times daily between 29 September and 26 October before returning to three-times daily.
The additional flights will be operated by a Boeing 787-9 Dreamliner aircraft featuring 271 economy seats and 28 business.
Etihad’s usual three-times daily Abu Dhabi-Heathrow service will continue to be operated by Airbus A380 aircraft.
The airlines says the extra flights have been timed to offer the most convenient onward connections to destinations in the Middle East, Africa, Asia and Australia.