Mark was born in Huntington, New York, on September 7, 1956. He is a graduate of Harborfields High School, class of 1974.

He is married with one teenage daughter, and currently lives in Cuyahoga Falls, Ohio

A journalism graduate of George Washington University, he has worked as a theater, film and television critic since 1979. He started his journalism career in the Washington, D.C. bureaus of Knight-Ridder Newspapers and the Associated Press. In 1983, after stints as the arts and entertainment editor at the Bristol Herald-Courier in Bristol, Virginia and the Kingsport Times-Times in Kingsport,Tennessee, he moved to the Akron Beacon Journal in Akron, Ohio as that newspaper's TV critic (later becoming its film critic). He currently is the television critic for The Plain Dealer in Cleveland, Ohio.

Dawidziak has written two non-fiction books about beloved TV characters: The Columbo Phile: A Casebook (The Mysterious Press, 1989), a history of Peter Falk's Lt. Columbo, and The Night Stalker Companion: A 25th Anniversary Tribute (Pomegranate Press, 1997), a history of the Carl Kolchak character played by Darren McGavin in two TV movies and the 1974-75 ABC series. His 2003 book, Horton Foote's The Shape of the River: The Lost Teleplay About Mark Twain (Applause Books) details the 1960 Playhouse 90 production on CBS.

In addition to Horton Foote's The Shape of the River: The Lost Teleplay About Mark Twain (Applause Books, 2003), he assembled Mark Twain's thoughts on writing and the writing process for Mark My Words: Mark Twain on Writing (St. Martin's Press, 1996). He also teamed with noted Twain scholar R. Kent Rasmussen for the chapter "Mark Twain on the Screen" published in A Companion to Mark Twain (Blackwell Publishing, 2005, edited by Peter Messent and Louis J. Budd). He has twice been the visiting Twain scholar giving the "Trouble Begins at Eight" lecture at Elmira College's Center for Mark Twain Studies. He has presented academic papers at three consecutive State of Mark Twain Studies conferences, most recently talking in August 2009 on the importance of Hal Holbrook's one-man show, Mark Twain Tonight!.

Dawidziak has been working for several years with Paul J. Bauer on a biography of Jim Tully, an Irish-American vagabond who became a literary superstar in the 1920s and '30s. Writing about his years on the road and the American underclass, Tully authored such works as Beggars of Life, Shadows of Men, Blood on the Moon and The Bruiser. To pave the way for the biography, which will be published by Kent State University Press in 2011, Black Squirrel Books issued 2009 reprints of Tully's Circus Parade (1927) and Shanty Irish(1928), edited with introductions by Bauer and Dawidziak.

Dawidziak has been on the other side of criticism as an actor. He met his wife, actress Sara Showman, through the stage. In 2002, they founded the Largely Literary Theater Company, a touring troupe dedicated to promoting literacy, literature and live theater. The company's artistic director, he frequently appears in Largely Literary productions as Mark Twain and Charles Dickens. His two-act adaptation of Twain material, Twain By Three, was performed at the 103rd Annual International Dickens Fellowship Conference (held at Case Western Reserve University in Cleveland, Ohio).

Dawidziak currently is teaching part time at Kent State University, in addition to writing for the Plain Dealer. He teaches the Reviewing Film and Television and Vampires in Film and Television courses. His first class was in the spring of 2009.

He frequently lectures and gives talks on Mark Twain, Charles Dickens, television and vampires. On October 23, 2009, Mark appeared at the Kent Stage, in Kent, Ohio, with the lecture "Haunted Theaters, Dracula & Me".

Mark is a longtime friend of Harlan Ellison and Richard Matheson (who has mentioned him in the dedication to two books). Mark screened a documentary about Harlan while visiting him in California and helped introduced the film, Dreams With Sharp Teeth, when it was screened at the Cleveland Public Library in 2007.