The game will be held at Eden Park on Tuesday 5 July, between the second and third Tests.
The tour will now see the Lions play seven provincial sides, as well as New Zealand Maori and the three Tests against the All Blacks. The Lions first match is against Bay of Plenty in Rotorua on 4 June with the final match, the third Test, in Auckland on 9 July. Kick off times for the matches are yet to be confirmed.
"Both the Lions and the NZRU were keen to schedule an additional match against one of the top provincial sides and I'm sure Auckland will provide them with a challenging match-up before the third Test,' New Zealand Rugby Union Deputy CEO Steve Tew said at a press conference held in Wellington today.
British & Irish Lions CEO John Feehan said there was no doubt that next year's tour would bring some challenging encounters not only at Test level but when the tourists face the provincial sides and the additional fixture against Auckland would prove to be no exception.
"This is something that both ourselves and the NZRU have been discussing for some time. The game provides the Lions with a tough clash prior to the third Test and gives not only the New Zealand public but the countless Lions tourists another opportunity to see the Lions in action".
Auckland has an enviable reputation against international touring sides, including six wins over the Lions in their thirteen encounters.
Also unveiled at the NZRU's press conference in Wellington was the ticketing policy in relation to the Lions. New Zealand rugby fans are to be given the best chance of getting to see the touring side through a public ballot for match tickets.
"This is the most eagerly anticipated rugby tour of recent times and there is a massive demand for tickets. We expect that demand will far outweigh supply and by holding a ballot, everyone will get the chance to buy a ticket," he said.
Ticket prices will range from as low as $10 for a children's ticket to a provincial match to $300 for a prime seat at a Test match.
An estimated 150,000 tickets will be available to Lions matches via the public ballot to the New Zealand Public.
The NZRU also announced that members of New Zealand's Rugby Community, season pass holders and residents living within the boundaries of the provincial unions hosting Lions provincial matches, will have a higher chance of success in the ballot through a preferential 'weightings' system.
"The New Zealand Rugby Community includes a number of groups, such as players, referees, managers and coaches at all levels, as well as the thousands of administrators and volunteers who give their time tirelessly to rugby in New Zealand. We want to reward them for their service," Tew said.