All of Delta's BusinessElite passengers and SkyMiles diamond and platinum medallion members arriving from the US have complimentary access into the new facility.
The lounge offers a number of amenities tailored to suit customers arriving in London from overnight flights.
Customers are invited to freshen up in one of 11 private showers featuring amenities by New York's Malin+Goetz and take advantage of on-site butler services including clothes press and shoe shine.
Meanwhile, multiple breakfast offerings are available including Starbucks coffee, lighter fare such as fresh fruit, pastries, yogurt and cereals and prepared to order a la carte items.
Wi-Fi is available throughout, plus a business center and a selection of the day's newspapers, and staff are on hand to assist with any future Delta travel plans.
Perry Cantarutti, senior vice president, Europe, Middle East and Africa, explains: “The Arrivals Lounge is a unique offering in the Delta portfolio and re-affirms the importance we place on London Heathrow.
"This new arrivals facility, when combined with multiple premium departure areas, Delta Sky Clubs and shower facilities offered throughout the Delta system, reinforces our commitment to London and the premium traveller."
BusinessElite customers also have private car access to the Virgin Atlantic Upper Class Wing on departure at Terminal 3, which enables them to go from car to clubhouse in less than 10 minutes.
The pre-booked service allows passengers to use the private security channel, beating the queues and leaving more time prior to boarding.
Last month, Delta announced it will begin flying non-stop between Philadelphia and Heathrow in April 2015, alongside its new flights from Seattle and Los Angeles to Heathrow.
The Delta Arrivals Lounge will be open daily from 6am until 2pm.