Burns has remained largely ignorant of Smithers's devoted adoration, much to Smithers's frustration. In later episodes, however, Burns appears to be somewhat wary of these gestures. Burns himself has been involved with several women and in "A Hunka Hunka Burns in Love", Smithers is noticeably disgusted when Burns starts looking for a female companion. Burns, for his part, views Smithers as somewhat of a lackey, albeit a highly valued one for his competence. He has "rewarded" Smithers's devotion with the future "honor" of being buried alive with him after he dies. Smithers has been shown to be somewhat dependent on his relationship with Burns. In "Homer the Smithers", Burns orders Smithers to take a vacation and Homer Simpson is hired as a temporary replacement. When Homer loses his temper and punches Burns in the face, Mr. Burns learns to become self-reliant and this results in Smithers being fired. Smithers decides that he needs to be Burns's assistant and eventually gets his job back. For all his sycophantic devotion to Mr. Burns, Smithers has been willing to challenge him on at least two occasions, most significantly in the "Who Shot Mr. Burns" episodes, where he opposed his employer's various evil schemes and was fired. As a result of his firing, Smithers became a "hideous drunken wreck and when Mr. Burns was shot later in the episode, Smithers thought he might have done it while he was intoxicated. When it was proven that he had not, Smithers seemingly forgave Burns and demanded that the culprit be brought to justice, offering a reward for the capture of the perpetrator.
Smithers's official job at the power plant appears to be that of executive assistant, which he says is "actually about 2,800 smaller jobs" responsible for monitoring employee attendance, and is often a disciplinarian and has won dozens of Employee of the Month awards. He has often hinted at wanting to be promoted to the position of executive vice president, but Burns has repeatedly squashed this dream, while whimsically bestowing the vice presidency on a dog. Smithers has the largest collection of Malibu Stacy dolls in Springfield and is the president of the Malibu Stacy fan club.
Waylon Smithers was partly based on how numerous Fox executives and staff members acted towards Barry Diller. The idea for Smithers's orientation came from Sam Simon, who proposed that Smithers should be gay, but the writers should never draw too much attention to it and should try to keep it in the back of their heads. The script for "Blood Feud" originally featured Smithers saying "Just leave me enough to get home to my wife and kids," but the line had to be cut for time. Smithers is voiced by Harry Shearer, who is also the voice of Mr. Burns. Shearer is often able to perform dialogue between the two characters in one take. Dan Castellaneta occasionally fills in for Shearer at table reads and voices Smithers. The name Waylon was first used in "I Married Marge" and comes from the puppeteer Wayland Flowers.
Smithers made his first appearance in "Homer's Odyssey", which was the third episode of the first season, although he can be heard over a speaker in The Simpsons series premiere "Simpsons Roasting on an Open Fire". In his first visual appearance in "Homer's Odyssey", Smithers was mistakenly animated with the wrong color and was made an African-American by Gyorgi Peluci, the color stylist. David Silverman has claimed that Smithers was always intended to be "Mr Burns' white sycophant, and the staff thought it "would be a bad idea to have a black sub-servient character" and so switched him to his intended color for his next episode. The first appearance of a yellow Smithers was "There's No Disgrace Like Home", the fourth episode of the first season.
Smithers's relationship with Mr. Burns has long been a running joke on The Simpsons. Smithers is an obedient and sycophant assistant to Mr. Burns. There have often been strong hints about Smithers' true feelings for his boss, with one of the earliest references being in the season one episode "The Telltale Head". Smithers's sexual orientation has often come into question, with some fans claiming he is a "Burns-sexual" and only attracted to his boss, while others maintain that he is, without a doubt, gay. During the Bill Oakley/Josh Weinstein era, they still tried to keep his sexuality mysterious and there was debate among the writers about his orientation. Al Jean, who thinks of Smithers as being a "Burns-sexual", felt that had Mr. Burns been a woman, then Smithers would not be gay. David Silverman, a former supervising director has said, "[Smithers] seems to be focused on one particular human, as opposed to anything beyond that. [Rather than being gay], he's sort of 'Burns-sexual.'" In a 2006 study conducted by the Gay & Lesbian Alliance Against Defamation, it was determined that nine of the 679 lead and supporting characters on scripted broadcast television were gay or lesbian. Smithers was not included among these nine characters, and it caused a mild online controversy. Patty Bouvier, Marge Simpson's lesbian sister, was included on the list. This is further backed up in one episode featuring a gay pride parade. A closet float (a pun of being 'in the closet') is shown, with two unseen voices that are obviously Smither's and Patty's, singing "We're gay, we're glad, but don't tell Mom and Dad."
The debate is referenced in "The Simpsons 138th Episode Spectacular", when the episode host, Troy McClure is answering viewer questions, and one that is asked is "What is the real deal with Mr. Burns' assistant Smithers? You know what I'm talking about." A montage of various clips that shows Smithers' lust for Mr. Burns follows, and in the end, McClure says "as you can see, the real deal with Waylon Smithers is that he's Mr. Burns's assistant. He's in his early forties, is unmarried, and currently resides in Springfield. Thanks for asking!
Several of the allusions to Smithers's sexuality have turned into battles with the censors. For example, in Smithers' fantasy of a naked Mr. Burns popping out of a birthday cake in "Rosebud", the censors had not wanted Mr. Burns to be naked. Another example is "Marge Gets A Job", which has a dream sequence where Smithers is sleeping and Burns flies through a window. The sequence shows Burns flying towards him and Smithers looking happy, but originally it went on for a few seconds longer. It had to be trimmed down due to scenes that showed "Mr. Burns land[ing] in a particular position on Smithers anatomy". There were also issues with "the lump in his bed", which the animators said had drawn as his knee, but the censors had misinterpreted.
Mostly in the early seasons, Smithers had a catchphrase, which comes from a recurring joke that Mr. Burns never remembers who Homer Simpson is. In some scenes, Smithers and Burns would watch Homer over a security camera and Burns would ask, "Who is that man?", to which Smithers would reply, "That's Homer Simpson, sir, one of your [insert drones, organ banks, carbon blobs, etc.] from sector 7G."
In the second season, the writers started to enjoy writing about Smithers and Burns's relationship, and the writers often pitched episodes with them as the focus, but many never came to fruition.
In 2004, Simpsons producers announced that one of the characters was going to come out of the closet. Speculation on who it would be was printed in newspapers throughout the United States and Canada (even claiming Smithers's "sexual orientation was about the worst-kept secret in Springfield,") as well as in Australia, New Zealand, Ireland, (the Irish Independent called Smithers "too obvious" a choice) and the United Kingdom. Despite Matt Groening joking that it would be Homer, The Boston Herald calculated the odds of several characters being gay, with Smithers at a million to one. PlanetOut hosted an online poll in the weeks prior to the episode to determine based on "cartoon gaydar" who was gay on the Simpsons, with 97% of the respondents choosing Smithers. Jenny Stewart, the entertainment editor at the site said of the poll, "We've never had such an avalanche of people voting in any of our polls as we did on The Simpsons. After the guessing, it was Patty Bouvier who came out.
In a 2007 article, Entertainment Weekly named Smithers the sixteenth greatest sidekick of all time. They have also described Smithers and Mr. Burns as being "TV's most functional dysfunctional couple". Star News Online named "Smithers' fey way" as one of the four hundred reasons why they loved The Simpsons. In a 2003 article, Entertainment Weekly named the Who Shot Mr. Burns? duo of episodes, in which Smithers was prominently featured, 25th best episode.