Facepalm, also known as Facepalming, is a slang term that refers to the act of placing one's face in one's hand, a form of nonverbal-communication common among many cultures. The action conveys a message of dismay and is often a reaction toward someone's momentary lapse of logic, judgment or memory. This reaction may be directed toward another person or be self-deprecating. Online, people post various reaction images, GIFs and videos of people performing the motion as memes to express embarrassment towards someone else's actions.
The facepalm, as an expression, existed long before the internet in both human and non-human societies. For example, an 1896 statue entitled "Caïn" by Henri Vidal, which resides in Tuileries Garden, Paris, France, was unveiled in 1896 (shown below, left).
One of the most famous and widely used variations of the facepalm comes from an episode of Star Trek: The Next Generation, which first aired on February 5th, 1990. The clip shows the character Captain Jean-Luc Picard (played by Patrick Stewart) reacting to a stressful situation by placing his hand on his face (shown below, right).
The website Word Spy cites a 2001 message board as the earliest usage of the expression. However, the actual post is no longer available.
Therefore, the earliest available usage of the term online was posted on February 10th, 2004, by Urban Dictionary  user Moondog. They defined the action as, "The act of dropping one's face / forehead into one's hand. Usually accompanied by a 'thunk' or a cr a cry of 'D'oh!' Usually written between asterisks in online conversation, to demonstrate an action." The post (shown below) received more than 2,500 upvotes.
The following year, on September 5th, 2005, the action was defined on the website Wiktionary as "To bring the palm(s) of one's hand(s) to one's face in mixed humor and disbelief (e.g.: when one is caught off-guard with a particularly bad pun)."
On May 1st, 2007, the website "Facepalm.com" was registered.
Two years later, on August 28th, 2009, Redditor  namsilat launched the /r/facepalm subreddit. The message board, as described by the moderators, is designed to share content that "cause viewers to facepalm."
In 2011, the Oxford English Dictionary added the word and defined it as "A gesture in which the palm of one's hand is brought to one's face as an expression of dismay, exasperation, embarrassment, etc."
One of the most popular facepalm images is one of Captain Jean-Luc Picard from Star Trek the Next Generation taken from the episode "Deja Q," which aired on February 5th, 1990. The earliest known reference to Picard's action as a "facepalm" was uploaded to YouTube by YouTuber Johan Jacobsen on May 21st, 2007. The post (shown below, left) received more than 489,000 views.
The following year, on January 14th, 2008, an article on Engagdet used a screenshot from the scene as a reaction to the headline (shown below, right). They wrote, "Most bizarre thing you'll read today: Mass Effect's 'virtual orgasmic r--e.'"
In May 2019, the website ThinkGeek began selling a bronze collectible bust of the infamous Star Trek facepalm (shown below). The bust weighs about one pound, is made of resin and retails for $69.99. In their description, ThinkGeek writes of the bust, "And since the dreaded Picard facepalm is such a big deal, we decided to “bronze it.” That way everyone can express their disappointment in us with bronzed Picards. Does it make the sting of embarrassment better or worse? We still don't know."