|Birthday||18th of an unknown month with 31 days|
|Hair color||Medium brown (youth and adulthood)|
Gray (elderly years)
|Favorite color||Green apple|
|Residence||Thora's childhood house (formerly)|
Grandma Thora's House, Elwood City
|Family||Thora's father (father)|
Thora's mother (mother)
Thora's brother 1 (brother)
Thora's brother 2 (brother)
Thora's brother 3 (brother)
David Read (son)
Jane Read (daughter-in-law)
Arthur Read (grandson)
D.W. Read (older granddaughter)
Kate Read (younger granddaughter)
Loretta's daughter (granddaughter)
David's brother (son)
Minnie Read (daughter)
Thora's mother's great-uncle (great-granduncle)
|Book debut||Arthur's Christmas|
|Cartoon debut||"Arthur's Spelling Trubble"|
|Voiced by||Joanna Noyes|
Michael Caloz (as a child)
She grew up in Elwood City. Since the town was founded recently, Arthur did not recognize it in early photographs. She was able to cross the street guided by denizens, law enforcement, and Zeppelins. She remembers her parents were very polite and understanding. She has three older brothers that she was jealous of. Because they did not find any durable toys, Thora spent her early childhood without any of her own. She eventually is gifted Clarissa and developed a love for Strawberries. The childhood version of Thora often has the same voice actor as D.W., such as Michael Caloz.
Later, Thora had three sons and two daughters, but her marital status has always been unknown. She continued to stay in Elwood City during David's childhood. During this time, they got to watch The Sugar Bowl and Wonder World get built, and a wildlife reserve cleared to build the nearby mall. She became a chaperone for her grandchildren  as well as a columnist. She knows several workers at the elementary school. She also spent time with her mother at the family reunion. After a while, Thora took in Killer, and a bat.
Thora is shown to be very kind, supportive, and understanding. She is very active and is not able to effectively cook. She will not hesitate to tell the truth about other people's mistakes, but at times speaks very softly.
She often babysits for her son during their many parties and other catering events. Because D.W. took a nap earlier, she decided to let her stay up for New Year's Eve. Arthur and D.W. rarely spend the night at Thora's. When they did, they saw how miserable she was, and threw her an annual surprise party. Thora talked D.W. out of running away. Thora is counted on for rescue.
She loves to play Bingo and is an expert at Marbles. She prefers to give her valuables as heirlooms. One example is Clarissa. In Family Fortune, she almost sells a treasured item at a travelling antique show instead.
She does not want to spend any time at a fancy restaurant if it means that her grandchildren might not be there.
- Mrs. MacGrady She plays Bingo and other activities with Mrs. MacGrady. Another time she worked with her at the bake sale.
- Ted Glass She has also been friends with Ted for a very long time.
- Grace Thora worked at her bake sale.
- Season 1
- Arthur's Spelling Trubble 10202
- Arthur Bounces Back 10802
- Arthur's Cousin Catastrophe 10902
- Arthur's Birthday 11001
- Arthur's Baby 11101
- D.W.'s Baby 11102
- Arthur Writes a Story 11201
- Arthur and the Crunch Cereal Contest 11601
- Arthur's Chicken Pox 11801
- Arthur's Almost Boring Day 12001
- The Half-Baked Sale 12001
- D.W.'s Snow Mystery 12201
- Bully for Binky 12301
- Arthur's New Year's Eve 13002
- Season 2
- Arthur's Lucky Pencil 20201
- D.W. the Picky Eater 20301
- Go to Your Room, D.W. (fantasy) 20402
- Arthur's Underwear (flashback) 20501
- Play it Again, D.W. (mentioned) 20602
- Arthur vs. the Piano 20801
- Lost! (fantasy) 20902
- D.W.'s Deer Friend (fantasy) 21101
- Grandma Thora Appreciation Day 21501
- Arthur vs. the Very Mean Crossing Guard 21801
- How the Cookie Crumbles 22001
- Season 3
- Season 4
- Season 5
- Season 6
- Season 7
- Season 8
- Season 9
- Season 10
- Season 11
- Season 12
- Season 13
- Season 14
- Season 15
- The Last King of Lambland (Cameo) 150302
- Season 16
- All About D.W. 160301
- Season 17
- Show Off 17001
- Season 18
- Season 19
- Arthur's Toy Trouble 190301
- Season 20
- That's MY Grandma! 200402
- Season 21
- Arthur's Perfect Christmas
- D.W. and the Beastly Birthday
- Arthur and the Haunted Tree House
- The Rhythm and Roots of Arthur
- An Arthur Thanksgiving
- She is named after author Marc Brown's own grandmother, Thora Brown.
- When she was a child, Thora had a close resemblance and voice to D.W. Read.
- In "D.W., the Picky Eater," it is revealed that Thora's birthday is on the 18th day of an unknown month with 31 days (there are 7).
- In "April 9th," David explains that when he was Arthur's age, Thora got into a car accident (though she wasn't hurt). For a time afterwards, David feared that Thora would get into another car accident.
- She originally is known to be a bad cook, but in later episodes she has been shown to be cooking better.
- In publicity/promotional materials, she is typically referred to as "Grandma Thora."
- In "Clarissa is Cracked," it is revealed she is a columnist, and as a young little girl, she looks like D.W. her age and both sound like each other sharing the same voice actor Michael Caloz.
- She was the one who gave Arthur his iconic yellow sweater.
- Thora's maiden name has never been revealed and it's never explained who her husband (the father of David and his siblings) was or if she was ever married.
- However given that her (paternal) Uncle Theo is a Read points to the evidence that Thora was born a Read.
- In "Buster's Best Behavior," Thora doesn't appear in the episode herself, Arthur transforms into her during the episode intro after he stole D.W.'s TV time.