Declan Hawthorne was an old friend of Carter Shepherd and father of Ivy Shaw.
In February 2024, Carter - the headteacher of Hollyoaks High School - enlisted Declan's 'help' with student Lucas Hay, upon discovering that Lucas had developed feelings for Dillon Ray. Whilst Carter had been taking a more gentle approach with their 'special classes', Declan was stricter: demanding eye contact, using openly homophobic language, and getting aggressive with Lucas's atheism. As Lucas spoke of his feelings for Dillon, Carter and Declan used Amy Barnes's death at the hands of her closeted husband Ryan Knight to convince him that homosexuality was sinful.
Declan joined Carter, his daughter Freya Calder, and his new girlfriend Maxine Minniver to celebrate Carter and Maxine's new relationship in March 2024. However, Maxine soon discovered that Carter had cheated on her with John Paul McQueen and informed Declan, who initiated an emergency meeting within their conversion therapy group. He attended a session with Lucas and gave him a cross necklace to connect him to the church.
In April 2024, Ivy - going by "Kitty Draper" - spotted Declan in The Dog in the Pond and told Freddie Roscoe about him: he tried to raise her religious and masculine, so she ran away from him when she transitioned. Carter called Declan to the school to speak to Ro Hutchinson, who had recently come out as transgender. Ro, however, refused to believe that Declan was a school inspector and attempted to capture evidence to expose him. Ro sent the footage to Kitty Draper, with Freddie Roscoe interrupting and violently threatening Declan into leaving. Declan obliged, but spotted Ivy whilst in the back of a taxi.
Declan visited Lucas in hospital in May 2024, after Lucas cut himself badly self-harming. Carter had been arrested for his criminal acts leading up to a pride event in the village. After attempting to convince Lucas to continue with his 'therapy', he then tried to convince Freya that her father was still a good man. As he prepared to leave the village, he kidnapped Ivy and held her locked up inside her bedroom at her former home, 12 Struther Road and refused to let Ivy take her hormones.
After the police arrived to arrest Carter Shepherd after his attempted murder of John Paul McQueen, Declan shouts at 'Ivan' for stealing his phone to call the police. It was then revealed that Ivy has 'proved' himself male once in the past after Declan forced Ivy to sleep with Lizzie Chen-Williams. Beau Ramsey saves Ivy after Declan tied her to the bed. Ivy tells Beau that her dad has been treating her like this for years and that Declan drove her mum away when she was younger and made it out like it was Ivy's fault and became a conversion therapist because of her.
After discovering a break-in to the house, Declan whacks Beau on the head with his 'Prayers for Ivan' book. After Ivy refused to be tied to the bed again, a scuffle between the two ensues. Beau comes in to rescue Kitty and whacks Declan on the head with the 'Prayers for Ivan' book. Declan falls and hits his head on the side of the bed frame and dies.