Lex Luthor, introduced in the
pilot as the son of billionaire
Lionel Luthor (
John Glover), is sent to
Smallville by his father to run the local fertilizer plant. As a child, he is caught in the first
meteor shower that renders him completely bald as well as providing him with perfect health. Years later as a young adult, Lex first meets Clark Kent (
Tom Welling) saving his life from drowning and the two quickly become friends. During the early seasons of the show, Lex's friendship with Clark inspires him to try to be a better person than his father, but his motives are usually driven by curiosity for the unexplained, like the day Clark rescued him from drowning. All the evidence points to Clark having been hit by Lex's car, but Lex refuses to believe that's what happened so Nixon attempts to expose Clark to everyone. Around the same time, Lex also enlists the help of Dr. Hamilton (
Joe Morton) to study the effects of the meteor rocks, finding an octagonal disc with unknown symbols imprinted on the disc's surface that match those on Clark's ship, while searching for traces of an alien ship that landed in Smallville in 1989. The disc is eventually stolen from Lex by Nixon in an attempt to open Clark's ship. In
season two, Lex's curiosity with the symbols continues. Lex first kills Nixon before the reporter can kill Jonathan for protecting Clark from Nixon. When Clark discovers the Kawatche Caves under a LuthorCorp construction site, Lex opts to be the
curator of the caves to preserve them after he notices symbols on the cave walls that match the symbols on the disc, as well as an octagonal shape in the wall of the cave that would fit the disc perfectly. His interest grows more and more when he finds Clark constantly in the caves, and later with a piece of paper that appears to indicate that Clark has deciphered the language on the cave walls, but Clark denies being able to read the language. Lex's
company eventually loses the Kawatche caves as Lionel has also developed an interest in the caves and the octagonal disc. During all this, Lex also met and courted
Dr. Helen Bryce (
Emmanuelle Vaugier) but Helen would try to kill him on their honeymoon.
Season three revealed why Lex endured Lionel's harsh parenting; his father blames him for his younger brother Julian Luthor's death but Lex took the blame to protect the true killer, his mentally unwell mother Lillian Luthor (
Alisen Down), from Lionel's wrath. Also, Lex's curiosity into the symbols (and Clark) leads to a blowout between the two. When Lionel gives Clark a key to a room in the Luthor Mansion where Lex has been collecting information on Clark's family, Clark informs Lex that their friendship "is over". In
season four, Lex replaces his father as LuthorCorp's CEO and turns his attention turns toward finding three ancient stones, which contain the same symbols as those in the cave and on the disc. He fails to find all three stones but suspects that Clark did, and used the stones to find the treasure of knowledge they were supposed to have led to, often having confrontations with
Jason Teague (
Jensen Ackles). Around this time, Lex's lifestyle of bedding women and then leaving them the next day would catch up to him when one (
Cobie Smulders) that he had previously slept with attempts to kill him after framing him for the murder of another one of the said women. In
season five, Lex becomes obsessed with uncovering Clark's secret; he breaks three
metahuman criminals out of
Belle Reve and sends them to the Kent Farm, where they hold several people close to Clark hostage. The scheme amounts to nothing, however, and Clark cuts Lex out of his life completely upon finding out. His curiosity into the symbols, which he believes to be alien in nature, results in
Brainiac (
James Marsters) arranging him to be possessed by the spirit of the
Kryptonian criminal
Zod. In
season six, Lex married Lana after deceiving Lana into being pregnant with his child. Upon learning the truth, Lana faked her own death and attempted to pin the murder on Lex.
Season seven displayed Lex's descent into darkness; he has a brother-like relationship with
Grant Gabriel (
Michael Cassidy), the new editor of the
Daily Planet who is actually a clone of Lex's late brother. Lex buys the
Daily Planet to which Grant attempts to keep Lex from being controlling, thus Lex has his brother's clone murdered and staged as a failed mugging. Lex then discovers that the previous symbols are connected to the secret organization Veritas, which his father is a part of; the Veritas members learned that an alien visitor known as "The Traveler" would arrive in Smallville during the meteor shower of 1989. At this time, Lex realizes that Lionel has been covering up the Traveler's existence and subsequently kills his own father for it. He eventually discovers that the Veritas members knew of a means to control the Traveler, so Lex sets out to find the device. The device, an orb he finds in the mantle above a fireplace in the Luthor mansion, leads Lex to the
Arctic where he ice burned his right hand, before entering the
Fortress of Solitude, where he is confronted by Clark. Having finally discovered Clark's secret, Lex uses the orb to bring down the Fortress around Clark and himself. In
season eight, Lex is missing and
Tess Mercer (
Cassidy Freeman) is put in charge as Lex's hand-picked successor. Tess wants Lex found, until Lex is revealed to have a surgically implanted nano-transmitter in Tess's optic nerve. Wanting revenge, Lex uses a kryptonite bomb to have Lana's stolen bio-enhanced suit, designed to absorb and emit kryptonite radiation, absorb the radiation to de-activate the bomb and subsequently never be able to go near Clark again without fatal effects.
Oliver Queen (
Justin Hartley) discovers Lex's location and uses a bomb to blow up Lex's travelling medical transport, seemingly killing him.
Season ten revealed that at some point prior, Lex manufactured a number of clones, but the majority of them are flawed and age at an accelerated rate. One clone of Lex (
Mackenzie Gray), aged approximately twenty years older than the original, attempted to get revenge on Clark by trying to kill
Lois Lane (
Erica Durance) but died before he could finish. The
two-hour series finale revealed Lex had a composite clone created from the best pieces of several others. Lacking a heart, the clone was kept on life support. An
alternate reality version of his father sacrifices himself to
Darkseid, receiving Lionel's heart and effectively resurrecting Lex. He speaks with Clark, telling his former friend he accepts they have a destiny as enemies, but neither of them can fulfill their roles unless Clark defeats Darkseid by inspiring humanity. Lex later meets with Tess and fatally stabs his sister, but Tess poisons him with a specialized
neurotoxin that removes all of Lex's memories. The series ends by shifting seven years into the future, where Lex has become the
President of the United States. ==Portrayal==