What is the origin of the phrase – my work here is done ? Context is usually after an individual creates deliberate chaos or confusion – and is said with a great deal of personal satisfaction. Literary ?? Movie ?? TV show catch-phrase ?? It’s driving us nuts. Does anyone know ?? 
It comes from old comic/cartoon super heros, sort of. The hero used to make some kind of corn ball speech after saving the day and leaving the scene. The shows you are seeing are just playing with that.
I thought it originated with the Lone Ranger radio serial.
That was my thought when I opened the thread, too. But this is the Straight Dope, where proof of “what everybody knows” is expected.
And I’ll lay odds that within 72 hours, somebody will come into this thread and say that it was a catch phrase derived from a line in the August 24, 1940 Lone Ranger program (date used solely as example, pulled directly from the trivia repository in my butt, and not to be taken seriously), or something of that same sort.
And 72 minutes after that somebody will show that Enkidu said the line to Gligamesh in a variant late-Sumerian manuscript that they translated themselves.
(While I found a citation to a specific script, the line was used repeatedly throughout the radio and TV series It did not appear in every episode, but was certainly used often enough to become a catch phrase.)
That was my thought as well. I entered the thread to post that same thing.
I vaguely remember seeing it in an article about “last words.” Now, you have the same recollection, only second-hand. 
During the late 1980s / early 1990 there was a Canadian comedy sketch group called “Kids In The Hall.” They still tour a bit.
One of their characters used to say “My work is done here” with great Significance in his voice after doing some goofy quasi-good yet utterly pointless deed. Notice the slight change in word order; perhaps that’s the Maple-Leaf version of the cliche.
I’m not suggesting they originated the phrase, but they certainly were one of many people who helped popularize it.
Wow – not only “within 72 hours” but within 101 minutes of my post. Thanks, Tom~!!!
Ok, I’m not playing Trivial Pursuit with you.
Edited title for clarity.
-xash
General Questions Moderator
In 1932, after learning he was suffering from a worsening spinal ailment that would cripple him for life, George Eastman, the founder of Eastman Kodak, shot himself to death. His suicide note said simply, “My work is done. Why wait?”
Tyrone Power as Zorro (1940).
Do you have a cite worth resurrecting this?
In Anthony Hope’s 1894 novel “The Prisoner of Zenda”, Rudolf Rassendyll says that to the King of Ruritania as Rassendyll prepares to return to England. (p.155 of the novel). The Lone Ranger used to say it, too or to include Tonto, he sometimes said “Our work here is done.” However, I have never found an earlier example than in the Hope novel.
“My work here is done” occurs in The Prisoner of Zenda, a novel written by Anthony Hope and published in 1894. The hero says it after rescuing the kingdom of Ruritania from a political coup, as he prepares to leave and return to his life as an English gentleman. Not many people today have heard of this novel, but it was extremely popular and influential at the time it was written and at least through the first half of the 20th century. I’m guessing, but it seems likely that all the comic book and movie characters who use this phrase got it from the book.