Debuting shortly before his wife, Susan Kennedy (Jackie Woodburne), he is the longest running continuously appearing character in the series' history.

[3] They felt that they needed to take the show back to its roots when it seemed that all the houses on Ramsay Street were populated with misfits and distant relatives.

[13] Karl and Susan have been caught in the nude together on three occasions; at the beach, in Lou Carpenter's (Tom Oliver) spa and when they went skinny-dipping in the bush.

"[15] Karl met his wife, Susan at university and they had three children together; Malcolm (Benjamin McNair), Libby (Kym Valentine) and Billy (Jesse Spencer).

Billy befriends Toadfish Rebecchi (Ryan Moloney), who Karl dislikes, while Libby falls for an older guy and Malcolm begins dating Danni Stark (Eliza Szonert).

However, when Karl saves Malcolm's life by performing a tracheotomy on him, he decides to resume practising medicine and takes over the lease on the surgery at the Lassiter's Complex.

When Malcolm leaves home, he sends his friend Joel Samuels (Daniel MacPherson) to Erinsborough to stay with Karl and Susan.

They decide to get back together, but keep their relationship a secret from Susan's stepchildren, Rachel (Caitlin Stasey) and Zeke (Matthew Werkmeister).

A few months later, Karl realises Zeke is suffering from anxiety disorder and he takes him back to the scene of the rafting accident to help him.

Following a fire at the Scully house, Karl comes up with a plan for a male nude calendar to help raise money for the repairs.

He makes a bet with Jade Mitchell (Gemma Pranita), who is overseeing the women's calendar, that whoever raises the most money will win the Men's Shed.

Susan invites Summer Hoyland (Jordy Lucas) to stay without consulting him and Karl later tells his wife that he thinks they are heading in different directions.

Karl gives Susan's friend, Jim Dolan (Scott Parmeter), some medical advice and manages to rile the new doctor, Rhys Lawson (Ben Barber).

Karl bonds with Susan's date, Bernard Cabello (Bruce Alexander) and Andrew Robinson (Jordan Smith) offers to manage the band.

After learning Susan has a separate bank account that contains her mad money, Karl is dared to spend big and so he invests in Daniel Robinson's (Tim Phillipps) Off Air bar.

Karl questions his colleague Maureen Knights (Judith Chaplin) about her son Cooper's (Charlie Hannaford) home life, after he suffers a head injury.

Karl befriends first year resident David Tanaka (Takaya Honda), who confides in him about his search for his father when he is caught looking at medical records.

Karl's ideas find support from Shane Rebecchi (Nicholas Coghlan), but he is fired after he is wrongly accused of removing the statue from the Lassiter's Complex.

Karl tries to raise finds for his new MRI screening project, despite Clive Gibbons (Geoff Paine), the hospital's COO, telling him it will likely fail.

Xanthe Canning (Lilly Van der Meer) finds him and calls the emergency services, but she is then forced to perform CPR when Karl's heart stops.

Karl has a minor health scare and Rita hires him an assistant called Patrick, who is actually Finn Kelly (Rob Mills), the man who tampered with Susan's medication in order to take her job.

Jemima comes to Erinsborough and ends up replacing Susan as celebrant at Aaron Brennan (Matt Wilson) and David Tanaka's (Takaya Honda) wedding.

[24] In 2007, Australian newspaper the Herald Sun placed Karl's affair with Sarah at number eight on their list of Neighbours Top Ten moments.

"[29] In 2021, Karl was placed eighth in a poll ran via soap fansite "Back To The Bay", which asked readers to determine the top ten most popular Neighbours characters.

[30] In a feature profiling the "top 12 iconic Neighbours characters", critic Sheena McGinley of the Irish Independent placed Karl as her eighth choice.

She stated that Karl has "pinballed from upstanding pillar of the community to alcohol dependent, to veg patch enthusiast, and back to being a conscientious doctor.

[33] In 2010, to celebrate Neighbours' 25th anniversary Sky, a British satellite broadcasting company profiled 25 characters of which they believed were the most memorable in the series history.

Now in his 18th year in the role, Alan Fletcher has charmed Neighbours viewers with his medical skills, smooth moves and his tendency to parent anyone who walks through the Kennedy door.

Now a smooth crooner and frequenter of student nights in the UK to boot, Fletch has made it to the top of our ultimate Aussie soap heart-throbs list.

Apart from a few filthy looks from Susan of course..."[36] Ben Pobjie of The Sydney Morning Herald thought Karl's "peculiar childlike enthusiasm that makes him such great comic relief" was "his most endearing feature apart from his tendency to periodically have affairs with younger women.