Luke was born to Lily Walsh and Damian Grimaldi, and was subsequently raised by Lily and Holden Snyder (see Holden Snyder and Lily Walsh). When Luke became a teenager, he came out to his parents Lily and Holden that he was gay. Eventually they accepted him.
Luke Snyder was originally born in 1995. Since then, his character has been SORASed two times; in 2001, when nine-year-old Christopher Tavani took over the role, and 2005, when fifteen-year-old Jake Weary played the part.
Luke confesses to killing Julia, believing that his mother is the real killer. In turn, Lily confesses to the murder herself, believing she is protecting Luke. Julia's ex-husband Les Sweeney is revealed as the true culprit. With the Holden/Lily divorce imminent, Lily begins to date Julia's brother, pilot Keith Morrissey. As had been the case with Julia, Luke is dead set against someone coming in and destroying his parents' marriage. To make himself feel better, Luke begins to drink, to the point of becoming an alcoholic. While in a drunken stupor, Luke finds himself on board one of Keith's airplanes. The plane lands in Mexico and Holden and Lily, who are falling back in love, quickly travel to Mexico to retrieve their son. Unfortunately, Luke contracts a kidney infection while out of the country and needs a donor.
Worried for Luke's new kidney, Holden and Lily determine that Kevin Davis, Luke's best friend, is a bad influence on him, and want Luke to cut all ties with him. One night, while sneaking out to see Kevin, Luke hits a young woman with his car. The woman turns out to be Jade Taylor, the daughter of Lily's twin sister Rose D'Angelo.
After Luke lies to Kevin that he and Jade are an item, Kevin reveals that he, too, has a girlfriend and no longer wants to hang out with Luke. A devastated Luke informs Jade, who thereupon attempts to convince Luke that he isn't gay by kissing him. Luke pushes her away, and Holden sees; Luke wanted to use that moment to come out to Holden, but a medical emergency with Lily prevents this. Observing the stress that Jade's presence creates for his parents, combined with the increased bickering between he and Jade, leads Luke to unload his problems and come out to his friend Will Munson, who advised Luke that the best thing for him to do was to be honest and tell his parents the truth.
When Luke finally comes out to Holden and Lily, he is a bit taken aback by their reactions. Holden is accepting and supportive while Lily has trouble dealing with her son being gay. Also accepting of him and his sexuality are his two grandmothers, Emma and Lucinda who give their full support to their grandson.
Nothing surprises Luke more, however, than when his birth father, a man who hasn't been in his life for many years, shows up in town a few weeks later.
Damien convinces Lily he will solve the "problem" with Luke and attempts to send him to a summer camp that advertises "gender re-alignment." Luke rebels against his mother, hurt by her reaction to his revelation that he is gay. Things are strained between them and Luke eventually agrees to go to the "summer camp" and goes upstairs to pack his things. Lily, discovering at the last minute that Damien has lied to her about the true purpose behind the "de-gaying" camp and regretting her alignment with him, rushes home in an attempt to reconnect with Luke. Still hurt and angry at his mother's continual rejection, believing she alone is behind the idea to send him away, Luke pushes a pregnant Lily away from him causing her to fall down a long flight of stairs and lapse into a coma.
At the hospital, Holden angrily confronts Luke about what could cause him to shove his mother down the stairs. Luke informs Holden that it was an accident and told him about the camp Lily wanted to send him to. Holden refuses to believe that Lily would send Luke to a place like that and is initially cold towards Luke. A sympathetic Damian steps in and offers Luke his unwavering support. He also offers him a place to stay.
As the weeks go by, Damian helps Luke avoid Holden since Luke is convinced Holden hates him. When a still-comatose Lily gives birth, Luke tries making up with Holden. It is then Holden and Luke have a talk about his moving in with Damian. Luke talks to his unconscious mother about his plans hoping she'll wake up. Luke later goes home with Holden and the baby and has an argument with him and leaves the house for good. Luke soon learns that Damian is dying and wants Luke to come with him to Malta. Holden later stops Luke and tells him that he thinks Damian is lying about his condition, once again Luke turns his back on Holden.
Luke finally finds out the truth about Damian. Luke and Damian have a falling out and Luke gives him what he had wanted all along...Luke's portion of the Grimaldi fortune. Luke realizes Damian was the cause of his mother being in a coma. Luke eventually has the chance to press charges against Damian, but decides against it, hoping to end his family's nightmare, saying as far as he is concerned Damian is nothing to him and he feels that Holden is his true father. He renounces the name Luciano Grimaldi, stating that he is Luke Snyder.
Things calm down for Luke for a while. His friends are comfortable with his sexuality, but more importantly, Lily comes out of her coma. Lily tells Luke that she does not blame him for her fall and that she understands his anger at her and she was only hesitant in accepting his sexuality because she was afraid of the prejudice and discrimination that he could face. They reconcile. The whole family is shocked, though, when Lily's search for Rose's real daughter (the young woman who Jade originally posed as) results in learning that Jade really is Rose's daughter, thus making her Lily's niece and Luke's cousin. The Snyders let Jade back into their home and Luke begins to befriend her again, but not without keeping his guard up.
Luke admits to Noah that he is attracted to him. He assumes the feelings are one-sided, since Noah is dating Maddie, but they have strong sexual chemistry. One day, while Luke was helping Noah tie his tie, Noah leans in and kisses Luke. Noah swears he is only playing a joke and is straight, but Luke is skeptical; soon thereafter, Noah admits that he in fact kissed Luke because he had wanted to. The tension between them continues to grow, with Noah getting jealous after he sees Luke talking to another gay man. Luke, already uneasy about not telling Maddie the truth, tells Noah he does not want to see him again after the internship is over.
When Maddie begins having doubts about her relationship with Noah, she asks Luke if there is anything going on between him and Noah. Not wanting to continue to lie to his friend, Luke states that he can't answer the question. Shaken, Maddie responds that he just did. Luke tries to comfort Maddie, but she leaves, saying she needs to talk to Noah.
When Maddie isn't even able to look Noah in the eye when she next sees him, Noah confronts Luke, asking him what he had said to Maddie that left her so cold towards him. Luke and Noah argue, and Noah leaves to find Maddie and try to resolve things.
Maddie and Noah break up, and Luke is finally able to talk to Maddie and help her understand that Noah's being gay has nothing to do with her. Because of this, Maddie is later able to tell Noah that she wants to be friends with him again at some point, and that he'd be lucky to have Luke if he'd let himself.
Shortly thereafter, Noah calls Luke to WOAK, where he is finally able to acknowledge that his relationship with Maddie is over, and that he is gay. Luke repeatedly offers Noah support and advice around coming out to his father. When Noah expresses that his biggest fear is that his father, his only family, won't accept him and he'd be left alone, Luke tells Noah that he isn't alone.
Noah and Luke later run into each other at WOAK again, and have an upbeat conversation about Noah's newfound comfort with himself. After Noah thanks Luke for his help, an awkward silence forms, and Luke seeks to excuse himself from the conversation, but Noah touches his hand, and the two share their second kiss — their first under open and honest circumstances. Their joy is short-lived, however, as they are interrupted by Colonel Mayer.
Colonel Mayer reacts harshly, calling Noah names and telling him that Noah is no longer his son. Later, however, he seemingly has a change of heart about both Noah's sexuality and his relationship with Luke, and invites the two to join him on a fishing trip. Mayer secretly plans to murder Luke while on the trip, but his plan is thwarted by Holden and Lily. Although Holden and Lily interrupt Mayer, they are unable to stop him from knocking Luke down a hill, leaving Luke paralyzed. Mayer later returns and attempts to administer a deadly dose of sedative to Luke in the hospital, but Lily once again interrupts, saving her son's life.
Luke initially refuses to begin physical therapy but changes his mind after Noah visits his bedside. Noah had kept his distance because he thought Luke would blame him for his condition, while Luke thought Noah could not be satisfied with a boyfriend in a wheelchair. The two express their true feelings to each other and officially become a couple. After being discharged, Luke moves to Snyder farm with his father and siblings after his parents' marriage begins to fall apart. Luke tries to convince his parents to reconcile, but to no avail.
Luke and Noah confront Colonel Mayer before he is sent to prison, and Luke is able to stand and profess his love for Noah during the confrontation. Noah isn't able to respond in kind, but asks Luke not to take it back. Noah continues to support Luke's physical therapy, and at Christmas Eve dinner, Luke is able to stand and walk in front of his family.
That night, Noah gives Luke a card expressing how he feels about him, and signs it "Love, Noah". Luke then expresses his love directly to Noah for the first time. The two lean in to kiss, but the camera pans away to show only mistletoe on screen.
With Luke out of his wheelchair, Luke and Noah share their first date and their first dance at the grand opening of Metro on New Year's Eve. A few days later, Noah asks Luke to get a place together. Luke is nervous that they'd be moving too fast, but after Noah expresses his loneliness and says that Luke is his only family, Luke seeks an alternate solution. He gets permission from his grandmother and asks Noah to move in with him and his family permanently at Snyder Farm.
Luke supports Noah and Ameera Ali Aziz, a young Iraqi woman with connections to Colonel Mayer, in their efforts to go visit the Colonel in prison, but the trio is attacked en route by bigots. Noah is badly hurt after being hit with a tire iron, but Luke manages to protect his friends, and prevents the men from kidnapping Ameera until Holden and Lily stumble across the scene and help. Luke commits to helping Noah as he supports Ameera's efforts to stay in the United States.
Luke struggles as the outsider in Noah and Ameera's marriage. The marriage finally comes to an end because of a bizarre kidnapping plot that ends with the apparent death of Noah's father, and Ameera's being taken into custody by police. Noah blames Luke for those outcomes, and asks him for a break, so that he can clear his mind. After being forced to hide his relationship for so long, Luke bristles at the idea of more time apart from Noah, and the two break up.
Luke interviews Cyndi Lauper for the Oakdale University student newspaper. She performs at Oakdale University's Gay Pride celebration, and dedicates True Colors to Luke, after seeing the way he looks at Noah. The dedication works, and Noah finds Luke and apologizes, telling him he wants them to be back together. The pair thank Cyndi, and tell her True Colors will now be their song. Luke, however, is soon crushed to find out Noah has enlisted in the Army.
Luke follows Noah to Chicago to convince him to forget about the Army, but fails. Luke returns to Oakdale devastated, but Noah returns, saying he couldn't go through with enlisting.
Luke, Noah and Lucinda begin working on establishing the foundation, hiring Brian Wheatley to run it. Luke struggles to build a working relationship with Brian after he suggests Luke and Noah be more discreet in their relationship, due to the conservative nature of the philanthropic community.