Gavin Sullivan

""Did you think I didn't know? All you'd been planning? Naughty girl...""

- Gavin to Kathy

""Hello princess""

- Gavin to Sharon

Gavin Sullivan is the controlling, manipulative third husband of Kathy Beale, the biological father of Sharon Mitchell (nèe Watts), stepfather of Ben Mitchell and Ian Beale and is an antagonist in British soap opera EastEnders, making his first appearance in August 2015.

He is played by Paul Nicholas who is known for playing Vincent Pinner in British sitcom Just Good Friends.

Gavin was first mentioned in 2000 after Kathy left Walford for South Africa with her and Phil Mitchell's son Ben. It was later believed that in 2006, Gavin and Kathy were killed in a car crash which resulted in Ben returning to Walfordd to live with his half-brother Ian Beale and later Phil.

However nine years later in February 2015, it was revealed that Gavin and Kathy were alive and that the car crash was a way to escape an insurance scam and that Kathy had been in contact with Phil for sometime. Kathy planned to fake her death in order to escape the controlling Gavin and return to Walford to be with Ian and Ben. However in August, after a botched money handover from Phil at St. Pancras station, Kathy runs into Gavin who reveals that he was aware of her plan to escape him and attempts to drive her to a small airfield so they can leave England. But Kathy causes the car they're in to crash, which puts them in hospital, but later Kathy discharges herself and disappears.

After leaving hospital, Gavin comes to Walford, believing Kathy will contact Phil. He follows Phil and his cousin Ronnie to a small hotel where he grabs Kathy and flees to the airfield, but is stopped by the Mitchells and Kathy returns to Walford with Phil. A week later, it is revealed that Kathy has snuck Gavin into her hotel room and he is controlling her again. Sometime later, Gavin along with two armed men kidnap Phil and Gavin threatens to kill him if Kathy doesn't follow his instructions and give him money. Kathy takes money from Ian's safe before going to the police to report on the kidnapping.

Ian contacts Gavin and tells him that he knows what he's been doing. It is revealed that Gavin locked Phil in a closet, but by the time the police arrive, Phil is not there.

On 29 October, Ben confronted Gavin and told him to leave which he seemly did by train. However at the end of the episode, he is shown to have returned.

On 30 October, Gavin comes to the Mitchell household and lock Phil upstairs and prepares to kill Kathy and Ben by setting fireworks in the kitchen. He tells them that he once lived in Walford and had a child, just before Phil's wife and Ben's stepmother Sharon comes in and Gavin greets her with "Hello Princess" (the same greeting Sharon's adoptive father Den Watts greeted her with) and thus revealed that he was Sharon's father.