Lydia Simmonds is a fictional character from the BBC soap opera EastEnders, initially played by Margaret Tyzack and then by Heather Chasen.

Described as "brilliantly funny" and a "cantankerous, rich old bag of a grannie", EastEnders star Natalie Cassidy (who plays Sonia Fowler) praised the introduction of Lydia, whilst a writer for the Daily Mirror said the bond between Lydia and Janine was the "most touching and entertaining in Soapland."

The character and casting were announced on 15 February 2011, and of her casting, Tyzack said "I am delighted to be joining a great British tradition and a fine company of actors", and Executive Producer Bryan Kirkwood said: "What a coup to have Margaret Tyzack starring in EastEnders.

Lydia has endless possibilities as a character, and I can't wait to see Janine meet her match.

"[4] The Mirror said if viewers thought "characters don’t come any more twisted than evil Janine, they haven’t met her granny yet.

"[3] EastEnders executive producer stated that Lydia was introduced to help explore Janine's fun side.

[10] It was announced that 83-year-old (at the time of casting) Heather Chasen, who was previously best known for playing "super bitch" Valerie Pollard in ITV soap opera, Crossroads,[11] would replace Tyzack in the role, beginning filming on 15 April[6] for scenes to be broadcast from 21 April.

Lydia died of natural causes, so Janine can't understand the police interest.

"[17] Brooks said of the storyline as a whole, "I absolutely loved exploring Janine's background, I wanted to figure out why she behaves like she does.

[20] Janine is said to be "shell-shocked" when Lydia dies and when Pat and Janine's husband Ryan Malloy (Neil McDermott) see her in The Queen Victoria public house, Ryan calls the police and accuses her of murdering Lydia in order to inherit her estate.

[20] Lydia's backstory states that she never wanted a son, Norman Simmonds (George Layton) and doted on her daughter June.

[21] Although Lydia loved June, she hated the man her daughter was married to, Frank Butcher (Mike Reid).

On the wedding of Prince William and Kate Middleton she attends Dot Branning's (June Brown) street party but insults her great-granddaughter Tiffany Butcher (Maisie Smith) so Dot wheels her to The Queen Victoria public house where she watches the wedding.

Later, Lydia then patronises everyone including Pat Evans (Pam St Clement), Frank's mistress when he was still married to June.

Lydia asks to see the sun rise and hear the dawn chorus, and Janine opens the window for her.

[1] A writer for the Daily Mirror branded Lydia "a cantankerous, rich old bag of a grannie", but added that she was "a lady bountiful, selfless philanthropist and all-round good egg.