Mario (Chris Pratt Chris Pratt) and Luigi (Charlie Dai Charlie Day) are two plumbers who live in Brooklyn. They have just started their own small company, but it is clear that their families do not fully support their cause. One day, at work, Mario and Luigi are sucked into a strange world by water pipes, and they are forced to part during the journey. Mario comes to the mushroom country ruled by Princess Peach Blossom (voiced by Anya Taylor-Joy Anya Taylor-Joy), while Luigi is unfortunately transported to the land of Kuba ruled by the bully (Jack Blake Jack Black).At this time, the cool bully is ready to attack the mushroom country, capture the princess and marry her, at this juncture, Mario's appearance brings hope to the peach blossom princess, she takes Mario to the jungle kingdom and asks for the support of the king and prince (Seth Logan Seth Aaron Rogen) there.

馬利奧（克裡斯·帕拉特 Chris Pratt 配音）和路易吉（查理·戴 Charlie Day 飾）是生活在布魯克林的兩名水管工，他們剛剛成立了自己的小公司，但很顯然，他們的家人並不完全支持兄弟兩人的這份事業。某日，在工作中，馬利奧和路易吉被水管吸入到了一個光怪陸離的世界之中，兩人在旅途中被迫分開，馬利奧來到了由桃花公主（安雅·泰勒-喬伊 Anya Taylor-Joy 配音）統治的蘑菇國，而路易吉則不幸的被傳送到了由酷霸王（傑克·布萊克 Jack Black 配音）統治的庫巴國。此時，酷霸王正準備大舉進攻蘑菇國，擄走公主並和她結婚，在這個節骨眼上，馬利奧的出現帶給了桃花公主希望，她帶著瑪麗奧來到了叢林王國，請求那裡的國王和王子（塞斯·羅根 Seth Aaron Rogen 飾）的支援。