Carl, a 78-year-old widower, ties thousands of balloons to his house to fulfill his lifelong dream of traveling to South America with his late wife. Accompanied by an enthusiastic boy named Russell who stowed away on the house, they embark on an adventure-filled journey across the skies. The film introduces several memorable characters along the way, including talking dogs, a large colorful bird, and an old explorer, as Carl and Russell navigate their unconventional voyage and form an unlikely friendship.