Flannery was born in Philadelphia, Pennsylvania. She attended Archbishop John Carroll High School in Radnor, Pennsylvania. She graduated from the University of the Arts in Philadelphia. Her family did own a bar (TA Flannery's) in downtown Philadelphia, but has since been sold. She is one of seven children in an Irish-American family.
Flannery is the only cast member from The Office who is actually from Pennsylvania, where the show is set.
A former member of The Second City's National Touring Company, Flannery is an original member of Chicago's Annoyance Theater, where she created over 15 shows including "The Miss Vagina Pageant" and "The Real Live Brady Bunch".
The Lampshades, her comedy lounge act with veteran improviser Scot Robinson, has been running in Hollywood at the iO WEST board for over four years and was seen at the U.S. Comedy Arts Festival in Aspen, Colorado.
Flannery played Neely O'Hara in Off Broadway hit Valley of the Dolls at the Circle in the Square Theatre in New York City and Los Angeles. Also in Los Angeles, she played the teen prostitute and Blair's sister in The Phacts of Life at the Renberg Theatre and in the Lily Tomlin/Jane Wagner production of Hildy, Hildy, Three Feet Under at The Evidence Room.
She is the musical director of the Los Angeles Drama Club, teaching Shakespeare to 5 year olds to teenagers.
- Finger Babies (2010) as Teacher
- You (2009) as Airline Counter Girl
- Coco Lipshitz: Behind the Laughter (2009) as Reporter
- Wild Girls Gone (2007) as Reading Circle #4
- Jesus People (2007) as Sharon Nyenhuis
- Danny Roane: First Time Director (2006) as Marla
- I'm Not Gay (2005) as Secretary
- The Heir Apparent (2005) as Heidi
- Carolina (2003) as Café Waitress
- Life Without Dick (2002) as Crampy Legs Partygoer
- Amy Stiller's Breast (2002) as Reporter
- Trick (1999) as Ridiculous Writer
- Can't Stop Dancing (1999) as Tonia
- The Office (2005-2013) as Meredith Palmer
Flannery currently appears as the alcoholic, divorced, single mother Meredith Palmer on the television comedy The Office. Before The Office, she made appearances on The Bernie Mac Show, Boomtown, Curb Your Enthusiasm, and Jimmy Kimmel Live. She currently blogs (sometimes as her Office character) on MySpace.
She has also appeared on The Jay Leno Show portraying Wendy in a skit at the time of the burger chain's 40th anniversary , Mother Earth in a skit on the November 19, 2009 episode and Mrs. Claus on December 21, 2009.
- Flannery's height is 5' 4" (1.63 m).