Over 100:  Jacques Barzun (educator & historian), Silvio Zavala (Mexican historian), Michio Mado (Japanese poet & 1994 Hans Christian Andersen Medalist), Bel Kaufman (“Up the Down Staircase”), Maurice Nadeau (French literary critic and historian), and Said Akl (Lebanese poet/playwright).

Kids' writers and illustrators over 90:

1913
Irving Adler (science writer)
Eleanor Means Hull ("In the Time of the Condor," 1961)
Sheilah Beckett (Canadian illustrator of Golden Books: "The Twelve Dancing Princesses," 1954)
Margaret Rau ("Holding up the Sky: Young People in China")

1914
Harriett Mandelay Luger (Canadian YA author: "Lauren," 1979)

1915
Joža Horvat (Croatian author and 2006 HCA nominee)
Charlotte Zolotow ("Mr. Rabbit & the Lovely Present," with Maurice Sendak, 1962)
Helen Doss ("The Family Nobody Wanted," 1954)
Jean Fritz (Historian: "The Double Life of Pocahontas")
Marc Simont (French illustrator of "Nate the Great" & 1957 Caldecott Medalist),

1916
Beverly Cleary ("Ramona the Pest"),
Asta Vender (Estonian illustrator)

1917
Margaret O. Hyde (Multi-science writer),
Pascuala Corona (aka Teresa Castello Yturbide, Mexican folklorist & 1996 HCA nominee)
Aldren A. Watson (Painter/woodcut artist: "Gulliver's Travels," 1947)
Barbee Carleton ("Mystery of the Witches' Bridge," 1967)
Frank Modell ("New Yorker" and "Sesame Street" cartoonist)
Carol Seeger Kendall (1960 Newbery Medalist: "The Gammage Cup")
Lillian Morrison (Poet & compiler: "I Scream, You Scream: A Feast of Food Rhymes")
Dahlov Ipcar (Painter/writer: "The Biggest Fish in the Sea," 1972)
Rhoda Blumberg (1986 Newbery Honor: "Commodore Perry in the Land of the Shogun")
Frances Wosmek (Artist/writer: "Sky High" aka "Twinkle Tot Tales" - 1949)
Ruth Robbins (Illustrator: "A Wizard of Earthsea" & 1961 Caldecott Medalist)

1918
Ann Tompert (folklorist, "The Little Fox Who Went to the End of the World")
Lyn Cook (Canadian YA novelist)
Joe Krush (Mary Norton's "The Borrowers" illustrator)
Margaret J. Baker (1963 Carnegie nominee, "Castaway Christmas")
James Aldridge (Australian YA writer)
Marcia Brown (reteller/illustrator & 3-time Caldecott Medalist: "Stone Soup")
Elisabeth P. Myers (Biographer: "Pearl S. Buck: Literary Girl")
Alice Provensen (Illustrator: Margaret Wise Brown's "The Color Kittens")
Sara Corrin (British editor: "Stories for Seven-Year-Olds and Other Young Readers")
Hap Gilliland ("Legends of Chief Bald Eagle" 2005)
Molly L. Cone ("Mishmash" humorous dog series)
Alton Raible (Illustrator for Zilpha Keatley Snyder)
Helga Sandburg ("Blueberry" 1963 - & daughter of Carl)
Daihachi Ohta (Japanese illustrator & HCA nominee, 1970, 2002, 2004, 2006)
Eva-Lis Wuorio (Finnish author of Canadian books: "The Island of Fish in the Trees" 1962)

1919
Jeanne Bendick (Science writer/illustrator: "Galen and the Door to Medicine," 2003)
Paule Cloutier Daveluy (Canadian YA author, "L'Ete enchante," 1958)
Antonio Frasconi (Uruguayan artist: 1959 Caldecott Honor: "The House That Jack Built")
Pete Seeger ("Abiyoyo")
Lennart Hellsing (Swedish poet and HCA nominee, 1994 & 2010)
Lynne Gessner (1977 Newbery nominee: "Navajo Slave")
Joe Lasker (Painter/writer: "Merry Ever After: The Story of Two Medieval Weddings," 1976)
Alison Jezard (British writer of "Albert" bear series)
Siny van Iterson (Dutch-Colombian mystery writer and 1972 HCA nominee)
Lee Kingman Natti (Horn Book editor and author of "The Peter Pan Bag," 1970)
Felice Holman ("Slake's Limbo," 1974)

1920
Muriel Leeson (British writer of Canadian books: "Promise-Keeper")
Margaret Hillert, ("Dear Dragon" preschool series, 1980s)
Hazel Krantz ("100 Pounds of Popcorn," 1961)
Edna Anita Miller (Writer/illustrator, "Mousekin" series)
Richard Adams (1972 Carnegie Medalist: "Watership Down")
Jean Kenward (British writer: "Ragdolly Anna" series)
Arnold Bare (Illustrator: 1944 Caldecott Honor: Lee Kingman's "Pierre Pidgeon")
Max Fatchen (Australian poet/writer)
Milton Dank (Biographer: "Albert Einstein" 1983)
James McCrea (Illustrator: "Shakespearean Sallies, Sullies and Slanders: Insults for All Occasions" by Ann McGovern, 1969)
Else H. Minarik (writer of "Little Bear" series with Maurice Sendak)
Barthe DeClements ("Nothing's Fair in Fifth Grade," 1981)
Margaret Paice (Australian writer/illustrator)
Margaret Bloy Graham (Canadian illustrator: Gene Zion's "Harry the Dirty Dog")
Michael Brown (Broadway lyricist & writer of "Santa Mouse," 1966, with illustrator Elfrieda De Witt)

1921
Louis G. Romano (“Gertie the Duck,” 1959)
Jan Slepian (“The Alfred Summer,” 1980)
Olga Cossi (“The Magic Box,” 1990)
Patricia Robins (aka Claire Lorrimer, British writer: “Sea Magic,” 1946)
Al Jaffee (MAD cartoonist)
Dorothy M. Martin (Protestant “Peggy” series, 50s-70s)
Feenie Ziner (“Cricket Boy,” with Ed Young, 1978)
Arabelle Wheatley (Nature illustrator)
Alice T. Gilbreath (1970s crafts/nature writer)
Pauline Clarke (1963 Carnegie Medalist: “The Twelve and the Genii”)
J.L. Cloudsley Thompson (British nature writer)
Ruth McCrea (Illustrator: “Japanese Fairy Tales” 1958)
George E. Laycock (Nature writer: "Never Pet a Porcupine," 1965)
Lois Lamplugh (British novelist: "Sean's Leap," 1979)
Annabel Johnson (YA novelist: "The Grizzly," 1964)
Jean Darby (Nature writer)
Helen Challand (science writer)
Alicia Morel (Chilean poet & 2000 HCA nominee)
Belinda Hurmence ("A Girl Called Boy," 1982)
Lee Roddy (Writer of Protestant mystery/adventure)
Martha Tolles ("Who's Reading Darci's Diary?" 1984)
Stella Pevsner (YA novelist: "And You Give Me a Pain, Elaine" 1978)
Val Biro (Hungarian writer/illustrator of British "Gumdrop" series)
Joyce Cooper Arkhurst (reteller of "The Adventures of Spider")
Leonard Kessler (Writer/illustrator of "Mr Pine" series)
Brent Ashabranner (Peace Corps, histories, biographies, sociology)
Tracy Sugarman (illustrator of Ann McGovern's "Robin Hood of Sherwood Forest")
Riki Levinson ("Watch the Stars Come Out" 1985)

1922
Louis Glanzman (Illustrator: "Pippi Longstocking")
Jean Bethell ("The Monkey in the Rocket," 1962)
Changmarin (Panamanian folklorist/illustrator)
Joan Heilbroner ("Robert, the Rose Horse," 1962)
Art Shay (Non-fiction photographer: "What Happens" series)
Mimi Korach (Illustrator: Donald Hall's "String Too Short to be Saved," 1960)
John Rowe Townsend (Carnegie Honours: 1963 & 1969)
Mollie Hunter (Scottish author & 1975 Carnegie Medalist)

Adult writers around the world (mostly from genarians.com)

In their 90s:

1912 M.H. Abrams

1913 Henry Bauchau, Boris Pahor

1914 Claire Martin, Martin de Riquer, Nicanor Parra

1915 Khushwant Singh, Jean Anglade, Leo Vroman, Herman Wouk, Grace Lee Boggs, María Rostworowski

1916 Edmund Morgan, Peter Geach, Dorothy Salisbury Davis, Albert Murray, Owen Chadwick, Bernard Lewis, Peride Celal, Neagu Djuvara, Eric Bentley, Jack Vance, Mary Stewart, Julian Kawalec, Doctor Tangalanga

1917 José Luis Sampedro , Fay Kanin, Eric Hobsbawm , Lise Nørgaard, Robert Conquest, Adolf Burger, Han Suyin, Richard C. Hottelet, Samuel W. Allen,  Diana Athill

1918 Daniil Granin, William Jay Smith, James MacGregor Burns, Richard Hoggart, Henri Vernes, René de Obaldia

1919 Peter H Abrahams, Lawrence Ferlinghetti, Alexander Eliot, Huston Smith, Michel Déon, Doris Lessing, Frederik Pohl

1920 Marcos Ana, Benoîte Groult, Marcel Reich-Ranicki, E.R. Braithwaite, P.D. James, Helen Thomas, Roger Angell

1921 Raymond Souster, Richard Wilbur, Wilson Harris, Marie Ponsot, Carol Emshwiller, Gabriel Okara, Daniel Berrigan, Farley Mowat, Ray Lawler, Edgar Morin, Julia Hartwig, Tadeusz Rozewicz, Ilse Aichinger, Sergeanne Golon, Dobrica Ćosić

1922 Helen Gurley Brown.

Lenona.