Took her first acting class with Sean Gunn (who stars as Kirk on WB's Gilmore Girls (2000)) at the age of six in St. Louis, Missouri. The class was taught by her mother, Anne Fischer. Jenna and Sean stayed in touch over the years and in October 2000 she married his brother, writer/director James Gunn The two are now divorced.
Graduated from Truman State University in Kirksville, Missouri
Daughter of Anne Fischer.
Originally enrolled at Truman State University as a Pre-Law student; later changed to Theatre.
Worked as a receptionist in various offices. Types 85 WPM with 90% accuracy.
Considered becoming a veterinarian due to her love for animals; ultimately opted for working with Kitten Rescue and being the proud owner of a dog and a cat (Andy, featured prominently with Jenna in 2006 issue of People Magazine's 100 Most Beautiful).
#37 in People Magazine's 100 Most Beautiful, 2006 issue.
First met ex-husband James Gunn at a script reading for The Specials (2000), which he wrote.
Mother Anne Fischer and younger sister Emily Fischer are both elementary school teachers.
Has one sibling - Emily Fischer, her younger sister.
Connected to many "Jims" in her life - her father Jim Fischer, her ex-husband James Gunn, Jim Zulevic (who cast her in The Specials (2000) and subsequently introduced her to James), and finally (and more famously known), her TV counterpart Jim Halpert (played by John Krasinski).
Former sister-in-law of Brian Gunn, Matt Gunn, Patrick Gunn and Sean Gunn.
Auditioned for the role of Sydney Bristow in Alias (2001), but was never called back. She later said, "They said they liked my acting, but I wasn't hot enough.
Fractured her back in four places after falling down a set of stairs at the NYC bar, Buddakan, on May 15, 2007.
Went to Nerinx Hall High School, an all-girls Catholic high school in Webster Groves, Missouri. Another alumnus is Marsha Mason.
On The Office (2005), the characters are all put off by Angela's (Angela Kinsey) creepy preoccupation with cute pictures of cats. In real life, Fischer has admitted she is an enthusiast of the same thing.
Is a fan of the NFL's Dallas Cowboys and an avid fan of the St. Louis Cardinals baseball team.
Is best friends with The Office (2005) co-star, Angela Kinsey, and is Godmother to Kinsey's daughter, Isabel.
Got engaged to Lee Kirk on June 30, 2009.
Was one week before her due date with her son Weston when she took maternity leave from filming The Office (2005).
Returned to work 5 weeks after giving birth to her son Weston to resume filming The Office (2005).
Along with her co-stars Owen Wilson, Christina Applegate and Alyssa Milano, Fischer is one of 4 actors from the film Hall Pass (2011) to become a first-time parent the same year the film was released.
Before becoming an actress, Jenna worked for 3 years at a car wash and also briefly tried her hand at being a telephone psychic when she first moved to L.A.
Purchased a $1.9m luxury home in the Glendale area of L.A., an estate that had once belonged to legendary baseball player and coach Casey Stengel. 
Gave birth to her 1st child at age 37, a son Weston Lee Kirk on September 24, 2011. Child's father is her 2nd husband, Lee Kirk.
She has German, Swiss-German, Scots-Irish (Northern Irish), Scottish, English, and Bohemian (Czech) ancestry.
(July 3, 2010) Married for the 2nd time her boyfriend of 2 years Lee Kirk following a 12-month-long engagement.
Gave birth to her 2nd child at age 40, a daughter Harper Marie Kirk on May 25, 2014. Child's father is her 2nd husband, Lee Kirk.
Returned to work 8 months after giving birth to her daughter Harper to begin filming You, Me and the Apocalypse (2015).
She and her ex-husband James Gunn remain close friends.