The 4th of July Lenny Lego special is the season 6 finale of The Lenny Lego Show.
As the episode begins, the first sequence, which replaces the traditional theme song, depicts Lenny and the gang singing the Star Spangled Banner, terribly. Lenny Lego and his friends all gather around and decide what they will do to volunteer for the upcoming 4th of July festival. Randy, with the help of Cody and Pig, decides to run the ferris wheel. Randy, Cody, and Pig end up assembling the wheel several times, only for it to be destroyed each time, all thanks to Mr. Fireman. Meanwhile, Mr. Ambulance ends up ruining over three-hundred hot-dogs after he microwaves them, which he did since he thought he was suppose to precook the hotdogs even though he misread the package which said "pre-cooked". His only option to precook the hot-dogs was the microwave as the grill had not yet arrived. A short time later, Mr. Fireman begs Lenny to buy the "Happy Hot-dog Man", a plastic imprinter which imprints man shapes onto hot-dogs, claiming they will make more money this way. Meanwhile Randy finally manages to assemble the ferris wheel without it getting destroyed by Mr. Fireman again. However, Mr. Fireman, when nobody is looking, decorates the wheel after himself, calling it "Mr. Fireman's Wheel of Terror", charging ten dollars a ride ("twenty with photo").
Soon the festival starts, which consists of a brand new portable roller coaster, Randy's ferris wheel, Mr. Fireman's dunk tank, Bull's hot-dog stand, and Cody's deep-fried cranberry sauce stand (which turns out to be a massive failure). A man finally buys some of Cody's deep fried sauce and immediately rides the roller coaster. Upon getting off, he pukes the red substance, which the ride operator mistakes for blood and calls the paramedics while shutting down the ride. Meanwhile, Randy's ferris wheel closes due to "inclement weather", which, in reality, is winds caused by the ceiling fan which turned on. The atrocious seven year old Pigpig then knocks Mr. Fireman into the dunk tank.
Soon, it is time for the fireworks to start. Lenny Lego, who volunteers to play Uncle Sam, realizes that someone forgot the Uncle Sam makeup, meaning Lenny has no choice but to appear as him in his common green clothes. Lenny excuses this by explaining he is celebrating America's birthday by keeping it clean (hence his green color). As the fireworks are about to start, Mr. Fireman accidentally knocks Lenny's head off his body. When Lenny asks him to put it back on, Mr. Fireman mishears Lenny and puts his head on top of the firework. The firework then flies out of the bedroom window and explodes in the sky as the town's people cheer.
The episode was a last minute decision and took significantly longer to film than other episodes. Filming took place all day July 3rd and editing was finished on July 4th, the same day the episode was released. The rides that were inside the bedroom were not taken down until 11:00PM on the night of July 3rd, as back up shots had to be taken before the rides were taken down. The "Queue bars", which were used for the ferris wheel, were reused for the roller coaster. Different shots combined together give the illusion that their are actually two different sets of bars, only in reality, only one set was used. The Queue bars remained intact, unused, until they were scrapped around 12:00PM July 5th.
The episode received a sequel titled "The Lenny Lego Show: the 4th of July Special 2", which aired on July 4th 2015.