Gavin Sullivan is a fictional character from the BBC soap opera EastEnders, played by Paul Nicholas.

Gavin is the third husband of Kathy Beale (Gillian Taylforth) and is also revealed as the biological father of Sharon Watts (Letitia Dean).

His storylines include his "abusive", "controlling" and "manipulative" relationship with Kathy, kidnapping recovering alcoholic Phil Mitchell (Steve McFadden) and getting him drinking again, and blackmailing Claudette Hubbard (Ellen Thomas).

His departure involves kidnapping Kathy, causing the death of his sister Margaret Midhurst (Jan Harvey) and being arrested after threatening to kill himself and Sharon.

[2] After Kathy makes attempts to contact someone at The Queen Victoria public house, Gavin arrives on Albert Square.

[13] Phil has a panic button installed and Kathy helps the police trace Gavin via his mobile phone.

He threatens to light fireworks inside the house, hoping to kill himself, Kathy, Ben, Phil and Dennis.

While Sharon talks to Kathy, she realises that Margaret Midhurst (Jan Harvey), the solicitor who arranged her adoption and who she has been visiting to track her father, is Gavin's sister.

Dot Branning (June Brown) then arrives, and eventually she remembers Gavin from his childhood in Walford, saying that he was a troublemaker who stole money from Ethel Skinner (Gretchen Franklin), and warns Kathy off getting involved.

Sharon then meets Gavin and gives him the money from her sale of her bar (to Vincent), and he asks for a reconciliation but she rejects him.

[33] Later, Gavin tells Kathy he has Dennis so she reluctantly gets in his car and is seen leaving by Buster Briggs (Karl Howman).

Kathy and Gavin arrive at a large country house that he bought with Sharon's money, and he locks them in, saying they can live there together.

"[36] Then, on 17 June, Treadwell-Collins posted on Twitter a photo of part of a script, featuring Gavin, and the caption "He's on his way...".

[37][38] The following day, 18 June, Paul Nicholas's casting in the role was announced, and it was confirmed that the character would play a major part in Kathy's return storyline.

"[37] Executive producer Dominic Treadwell-Collins said: "We are all thrilled that Paul has agreed to join our cast to play Gavin.

He said that when he joined the cast, he met the writers who explained the character to him and gave him a "really good insight into where they wanted it to go" and added, "It is nice to be involved in something so successful and that people actually watch.

"[43] Discussing this comparison, Rachel McGrath of The Huffington Post UK said, "He makes the murderous, abusive, rapist Archie look like a child's cuddly toy.

"[44] Vicky Prior from the Metro called Treadwell-Collins' claim "bold [...] for a show that has produced some of TV's most iconic villains", and included in her list Nick Cotton (John Altman), Archie (Larry Lamb), Lucas Johnson (Don Gilet), Trevor Morgan (Alex Ferns), Phil Mitchell, Grant Mitchell (Ross Kemp), Vincent Hubbard (Richard Blackwood), Janine Butcher (Charlie Brooks), Chrissie Watts (Tracy-Ann Oberman), Ronnie Mitchell, Michael Moon (Steve John Shepherd), Yusef Khan (Ace Bhatti) and Babe Smith (Annette Badland), saying that "I don't think Gavin will find it easy to earn a place in Walford's Rogues Gallery.

"[45] Digital Spy's Daniel Kilkelly said that the script snippet posted online by Treadwell-Collins "hinted that the character will be a formidable force".

[49] Harry Reid, who plays Kathy and Phil's son Ben Mitchell, called Gavin "a nasty bloke with an edge to him.

[75] Several news outlets reported speculation that Gavin could be the birth father of Sharon Watts (Letitia Dean).

Treadwell-Collins' comment that the character would "have a little foot in the past and a foot in the present" and is "holding the key to many more of the Square's secrets" caused David Brown, writer for Radio Times, to wonder what Gavin's connection to the past would be, saying "it's surely no coincidence that Sharon has recently been searching for her birth dad—a man who we know to also be called Gavin."

Carl Greenwood from the Daily Mirror said that "Two huge EastEnders storylines could be set to converge" if Gavin is Sharon's father.

[90] Gavin's final storyline sees him kidnapping Kathy, killing his sister Margaret Midhurst (Jan Harvey) and being arrested.

"[97] In February 2021, Dean and Taylforth were photographed filming on-location scenes which depicted Gavin's wake, and Digital Spy confirmed that the character had been killed off off-screen.

"[79] Frances Taylor, writing on BT Group's website, said that Gavin's introduction "got the nation talking about EastEnders for all the right reasons".

We've watched Kathy mither on about him for weeks, but the story only truly came to life when Gavin uttered the immortal wirds "'Ello Princess" to stunned daughter Sharon.

"[101] However, the following day she posted, "[To be honest] now I'm not pissed as a stoat, [I] think Gavin manipulating Sharon will be cruel & intriguing".

"[103] In February 2016, Laura-Jane Tyler from Inside Soap said, "We're in awe of Gavin's ability to glide in and out of Walford houses undetected, as if he's wearing a magical raincoat of invisibilty.

"[104] In June 2016, Sophie Dainty from Digital Spy included Gavin in a list of 10 soap opera villains she hoped would receive their comeuppance, opining that Gavin had not made "Archie Mitchell look like a care bear" as promised, adding that the fact that "he hasn't really done very much at all [...] leaves us feeling a little on edge", adding that "until he's humbled for good, we are fearful for those that have 'wronged' him.