The line’s newly-refurbished ferry, Isle of Inishmore, will sail the route five-times-daily, starting 29 June.
Services will depart Dover at 4.30am, 9.20am, 2.10pm, 6.55pm and 11.40pm, with each crossing taking approximately two-and-a-half hours.
Fares lead in from £69 for cars.
Nora Costello, Irish Ferries consumer marketing and sales director, said the new route would create more choice for people planning to travel to France later this year.
The ship features a new club class lounge, with 360-degree sea views.
Upon announcing the route in March, Irish Ferries said additional capacity would follow.
