|“||That boy was born lost, like his Daddy. He's been slipping through my fingers ever since the day I gave birth to him.||”|
|“||I'm just a bit sick of it all... The killing||”|
Nick Clark is a 19-year old former drug addict. Before The Fall his mother, Madison, sent him to rehab several times, but Nick had reached a point where no one could tell him what to do or force him into recovery — he would have to do that all by himself. Nick wants to prove he can rebuild his life – and, ironically, the apocalypse may provide him with that opportunity. 
|“||Madison's screwed up teenage son. He’s too old to stay home, too scared to flee...pretty much a parent’s worst nightmare. He has flunked out of college, had a lot of trouble, got mixed up in some bad elements, and is definitely the problem child. And it’s exacerbated for him to be next to this perfect sister who seemingly doesn’t have anything going on in her life that is negative.||”|
— Robert Kirkman, Exclusive Intel
Nick and his sister Alicia have an obviously close relationship that's strained because of Nick's addiction to heroin and because of his lifestyle. In contrast to him, Alicia is trying to achieve things and get to college, Nick sees her as a reminder of everything he can’t be. For her part; at the beginning of Season 1 while she obviously cares for him, Alicia does not see what can be done to help Nick, and thinks that her mother (Madison) will not succeed in her attempts to help him now that he is an adult. She sticks by him though, when the soldiers come for him for instance. ("Not Fade Away") in season 3 they become close again.
Nick is her son and they have a close relationship despite the problems Nick has. Her outburst and loss of control with him during "Not Fade Away" seems to be an isolated incident, so far.
Nick appears to resent and mistrust Travis. Travis tries to help Nick and readily takes responsibility for him and helps him when he can, staying with him at the hospital, investigating the abandoned church and then arriving to help him towards the end of "Pilot" when Nick calls after killing Calvin.
During the first half of Season 2, Nick and Ofelia are seen to talk more and develop a friendship. Nick shows concern for Ofelia's injury (shot in the shoulder in the Season 1 episode "The Good Man") and offers support and advice. Ofelia is sometimes physically to to Nick, touching his arm just before they sit down to eat on The Abigail and when she goes to the shrine, in the episode "Sicut Cervus", to pray to her mother it's Nick she takes with her.
Gloria was Nick's girlfriend before her death and was expecting to see her near him when he awoke at the beginning of "Pilot". He is very shocked to see her eating a dead body when he finds her - but he does not appear to grieve for her either then or later on in the way you might expect if he and Gloria had been close friends or boyfriend and girlfriend. However... Frank Dillane, who plays Nick has said in interview that "A lot of the stuff that drives Nick and makes him so troubled is his father dying and his girlfriend turning. He doesn’t really have much to live for."
Calvin is Nick's drug dealer and former friend. At the beginning of Season 1 Nick still thinks that Calvin is his friend.
Nick's relationship with Strand appears to be one of 'mutual benefit,' in that, Strand recognised Nick had the skills he (Strand) required to get a job done and, in exchange, Strand would help Nick escape the compound they were being held in. Strand later told Nick's mother, Madison Clark, that while she knew Nick his whole life, she never saw his true potential, while Strand saw it within five minutes of meeting Nick-- even when Nick was in the depths. of withdrawal.
|Season 1 appearances|
|Pilot||So Close, Yet So Far||The Dog||Not Fade Away||Cobalt||The Good Man|
|Season 2 appearances|
|Monster||We All Fall Down||Ouroboros||Blood in the Streets||Captive|
|Sicut Cervus||Shiva||Grotesque||Los Muertos||Do Not Disturb|
|Pablo & Jessica||Pillar of Salt||Date of Death||Wrath||North|
|Season 3 appearances|
|Eye of the Beholder||The New Frontier||Teotwawki||100||Burning in Water, Drowning in Flame||Red Dirt|
|The Unveiling||Children of Wrath||Minotaur||The Diviner||La Serpiente||Brother's Keeper|
|This Land Is Your Land||El Matadero||Things Bad Begun||Sleigh Ride|
|Clark family||Nicholas Clark • Madison Clark • Alicia Clark • Stephen Clark|
|Males||Travis Manawa • Nicholas Clark • Art Costa • Calvin • Christopher Manawa • Matt Sale • Victor Strand • Richards • Jones • ICU Doctor • Tobias • Melvin Allen • Castro • Druggie 2 • Faculty Member • Rocky Knath • LAPD Unit • Russell • Henderson • Old Man • Brandon • Dominic Fratto • Pale Face Junkie • Lab Coat • Peter Dawson • Bystander • LAPD Water Uni 1x02 • Patrick Sutherland • Patrick Tran • Neighbor|
|Flight 462||Nicholas Clark • Brenden Meyer • Jake Powell • Deirdre • Alex • Marcus • Suzanne • Connie • Michelle Ang • Anthony • Phoenix • San Francisco • Los Angeles Airport • Alan (Flight 462) • Jake's Mother • TruWest Airlines Flight 462 • Tom • Ian • FAA|
|Alive||Nicholas Clark • Madison Clark • Alicia Clark • Victor Strand • Richards • Jones • Daniel Salazar • Tobias • Castro • Faculty Member • Neighbor • Girl With Doll • Andrew Adams • Cole • Maria Thompson • Neighbor 1 • Thompson Daughter 1 • Thompson Daughter 2 • Johnson • Alex • Jack Kipling • Harry Geary • Seth Geary • Vida • Sofia • Geary family • Luciana Galvez • Juan • Elena Reyes • Hector Reyes|
|Los Angeles residents||Travis Manawa • Nicholas Clark • Madison Clark • Art Costa • Alicia Clark • Calvin • Christopher Manawa • Matt Sale • Liza Ortiz • Ofelia Salazar • Gloria • Bethany Exner • Victor Strand • ICU Doctor • Griselda Salazar • Tobias • ND Infected Woman • Melvin Allen • High School Student • Physics Teacher • Cheer Captain • Druggie 2 • Faculty Member • Rocky Knath • LAPD Unit • National Guard Driver • Russell • Henderson • Old Man • Nurse|