The game will be broadcast live on BT Sport.
The League General Manager Mark Ives added: “It is a fantastic sporting arena with a rich history and very befitting of our showpiece Promotion Final.
“Whilst we don’t know who will get to the Promotion Final yet, what we can now promise is a stadium worthy of hosting such a huge game."
Graham Gilmore, CEO of London Stadium, said: “We are proud to be hosting the National League play-off final this year, with the contenders vying for that coveted place in the Football League. We have witnessed some truly epic matches at our venue this season and this match will be another one of those special occasions at London Stadium.”
Ives added: “Last season was a huge success and I expect an even better occasion this time around."
The National League play-offs will get underway on Wednesday, May 25 with the teams who finish fifth and sixth playing each other, while the teams who finish fourth and seventh playing the following night.
The winners will then take on the teams who finish second and third over the weekend of the 28th.