The competition was announced on Facebook yesterday (6 April) by Spanish footballer Andres Iniesta, who visited Barcelona as part of Nissan's activation to ask fans for selfies.
As the league’s automotive sponsor, Nissan will fly 25 supporters to Milan’s San Siro stadium to wave the UEFA flag during the half-time show.
Fans have until 13 April to enter the competition, by posting a selfie into the comment box on Nissan's Facebook page.
In the second part of its campaign, the car brand is offering fans the opportunity to get their names printed onto the flag itself, which will be available to view in a high-definition photo from the event.
Ahead of the semi-finals, Nissan's brand ambassador Thiago Silva – a fellow footballer – will hit Paris to ask fans for their autograph.
He will then tell them to how enter the competition, which can be achieved via the brand’s Facebook page or website before 26 April.
Both elements of the campaign will be promoted by Nissan’s European dealerships.
Jean Pierre Diernaz, VP for marketing at Nissan Europe, said: "As part of our UEFA Champions League sponsorship, fans are at the heart of what we do at Nissan, and we’re constantly innovating to ensure we offer the most exciting experiences possible for these supporters.
"No other sponsor other than Nissan can make this promise to fans, to be stood on the centre circle of the pitch during the most watched sporting event of the year."
At the final Nissan will also be collecting fans' biometric data for its Excitement Index, which it is creating with scientists at Loughborough University in a bid to understand what constitutes the perfect game of football.