Here's the list of books illustrated by Wesley Dennis that I've been able to compile. I read a newspaper article that stated he had illustrated over 150 books. Maybe it was an exaggeration, but I've found 106 so far. If you know of any others, please drop me an email.

Title Author © Publisher
Album of Horses Marguerite Henry 1951 Rand McNally
Always Reddy (Shamrock Queen) Marguerite Henry 1947 Whittlesy House
Animal Story Book Watty Piper 1954 Platt & Munk
Benjamin West and His Cat Grimalkin Marguerite Henry 1947 Bobbs-Merrill
Black Beauty Anna Sewell 1946 World Publishing Co.
Black Fury Peggie Cannam 1956 Whittlesey House
Black Gold Marguerite Henry 1957 Rand McNally
Blue Smoke Dorothy Lyons 1953 Harcourt, Brace & Co.
Bluegrass Champion (Harlequin Hullabaloo) Dorothy Lyons 1949 Grosset & Dunlap
Book of Ponies Suzanne Wilding 1965 St. Martin's Press
Born to Trot Marguerite Henry 1950 Rand McNally
Bright Wampum (Cover & Frontispiece Only) Dorothy Lyons 1958 Harcourt, Brace & Co.
Brighty Marguerite Henry 1953 Rand McNally
Bronco Charlie - Rider of the Pony Express Henry Larom 1951 Whittlesey House
Cammie's Challenge Jane McIlvaine 1962 Bobbs-Merrill
Cammie's Choice Jane McIlvaine 1961 Bobbs-Merrill
Cavalcade of Horses Florence Peterson & Irene Smith 1961 Thomas Nelson & Sons
Cinnabar the One O'Clock Fox Marguerite Henry 1956 Rand McNally
Copper Khan Dorothy Lyons 1950 Harcourt, Brace & Co.
Crazy About Horses Shannon Garst 1957 Hastings House
A Crow I Know Wesley Dennis 1957 Viking Press
Dark Sunshine Dorothy Lyons 1951 Harcourt, Brace & Co.
Davy's Little Horse Louise Lawrence Devine 1956 Rand McNally
Dear Readers & Riders (Dear Marguerite Henry) Marguerite Henry 1969 Rand McNally
Dugan and the Hobo Jocelyn Arundel 1960 Whittlesey House
Favorite Animal Stories (The Children's Hour) Marjorie Barrows, editor 1953 Spencer Press, Inc.
Five O'Clock Charlie Marguerite Henry 1962 Rand McNally
Flip Wesley Dennis 1941 Viking Press
Flip and the Cows Wesley Dennis 1942 Viking Press
Flip and the Morning Wesely Dennis 1951 Viking Press
Fools Over Horses Helen Orr Watson 1952 Houghton Mifflin
Frog - The Horse Who Knew No Master (Cover) Col. S.P. Meeks 1965 Knopf
The Ginger Horse Maureen Daly 1964 Dodd, Mead & Co.
Golden Sovereign Dorothy Lyons 1946 Harcourt, Brace & Co.
The Golden Stallion Theodore Waldeck 1947 Viking Press
Halfway to Heaven Ruth Adams Knight 1952 Whittlesey House / McGraw Hill
Holiday Wesley Dennis 1946 Viking Press
A Horse Called Mystery Marjorie Reynolds 1964 Harper & Row
The Horseman's Companion Margaret Cabell Self 1949 A.S. Barnes & Co.
The Horseman's Encyclopedia Margaret Cabell Self 1946 A.S. Barnes & Co.
The Ice Bird - A Christmas Story Pauline Innis 1958 Western Printing & Lithographing Co.
I'll Take Cappy Lee McCabe & Norbert Fagan 1948 Whittlesey House
The Illustrated Marguerite Henry Marguerite Henry 1980 Rand McNally
Java Jive (Cover & Frontispiece) Dorothy Lyons 1955 Harcourt, Brace & Co.
Jingo - Wild Horse of the Abaco Jocelyn Arundel 1959 Whittlesey House
Justin Morgan Marguerite Henry 1954 Rand McNally
Justin Morgan Had a Horse Marguerite Henry 1945 Wilcox & Follett
Kentucky Derby Champion (Edited "Old Bones") Mildred Pace 1993 Jesse Stuart Foundation
Kickapoo Miska Miles 1961 Little, Brown & Co.
King of the Wind Marguerite Henry 1948 Rand McNally
Lance and Cowboy Billy Jack Holt & Carolyn Coggins 1950 Whittlesey House
Lance and His First Horse Jack Holt, Carolyn Coggins & Wesley Dennis 1949 Whittlesey House
The Land Beyond Ruth Adams Knight 1954 Whittlesey House
The Little Hawaiian Horse Wilma Pitchford Hays 1963 Little, Brown & Co.
The Little Horse That Raced A Train Wilma Pitchford Hays 1959 Little, Brown & Co.
Little Hurricane Happy Wilma Pitchford Hays 1965 Little, Brown & Co.
The Little Lone Coyote Wilma Pitchford Hays 1961 Little, Brown & Co.
Little-Or-Nothing From Nottingham Marguerite Henry 1949 Whittlesey House
Living Together in Town and Country Prudence Cutright, W.W. Charles & MacKnight Clark 1944 MacMillan
Lord Buff and the Silver Star George Agnew Chamberlain 1955 A.S. Barnes & Co.
Midnight Moon (Cover Only) Dorothy Lyons 1960 Harcourt, Brace & Co.
Mighty Mo - The Story of an African Elephant Jocelyn Arundel 1961 Whittlesey House
Misty of Chincoteague Marguerite Henry 1947 Rand MCNally
Misty Treasury Marguerite Henry 1982 Rand McNally
Muley Ears Marguerite Henry 1959 Rand McNally
My Brimful Book Dana Bruce (editor) 1960 Platt & Munk
My Brother Mike Doris Gates 1948 Viking Press
My Dog Lemon Ray Holland 1945 A.S. Barnes & Co.
North Fork Doris Gates 1945 Viking Press
Now Listen Warden Ray Holland 1946 A.S. Barnes & Co.
Old Bones the Wonder Horse Mildred Pace 1955 Whittlesey House
Once a Cowboy Charles Martin 1948 Viking Press
One Man's Horse (From "Born to Trot") Marguerite Henry 1977 Rand McNally
Palomino and Other Horse Stories Wesley Dennis (editor) 1950 World Publishing Co.
Pictorial Life Story of Misty Marguerite Henry 1976 Randon House
Prairie Colt Stephan Holt 1947 Grosset & Dunlap/td>
The Pup Who Became a Police Dog Wilma Pitchford Hays 1963 Litlle, Brown & Co.
Red Embers Dorothy Lyons 1948 Harcourt, Brace & Co.
The Red Pony John Steinbeck 1945 Viking Press
Red Tartar Page Cooper 1957 World Publishing Co.
Ride Like an Indian Henry Larom 1958 Whittlesey House
Riders of the Gabilans Graham Dean 1944 Viking Press
Sea Star Marguerite Henry 1949 Random House
See a White Horse Miska Miles 1963 Little, Brown & Co.
Shoes for Punch Jocelyn Arundel 1964 McGraw-Hill
Silver Birch (Cover Only) Dorothy Lyons 1939 Harcourt, Brace & Co.
Simba of the White Mane Jocelyn Arundel 1958 Whittlesey House
The Small War of Sergeant Donkey Maureen Daly 1966 Dodd, Mead & Co.
Smoke Rings (Cover & Frontispiece Only) Dorothy Lyons 1960 Harcourt, Brace & Co.
Star - The Story of an Indian Pony Forrestine Hooker 1949 Doubleday
Stormy Marguerite Henry 1963 Rand McNally
Summerfield Farm Mary Martin Black 1951 Viking Press
That Colt Fireplug Belle Coates 1958 Scribner's & Sons
The Story World (The Child's World Series) Ruth Tooze (editor) ? ?
Three Great Horse Stories Mildred Pace, Henry Larom & Peggie Cannam 1955 McGraw-Hill
TickTock and Jim Keith Robertson 1948 Grosset & Dunlap
Tony the Pony Lillian Moore 1959 Whittlesey House
Trails to Treasure David Russell, et. al. 1953 Ginn & Co.
Treasury of Dog Stories Frances Cavanah & Ruth Cromer Weir (editors) 1947 Rand McNally
Tumble Wesley Dennis 1966 Hastings House
Twenty-Four Horses - A Treasury of Stories Frances Cavanah 1950 Rand McNally
Wagging Tails (Album of Dogs) Marguerite Henry 1955 Rand McNally
White Stallion of Lipizza Marguerity Henry 1964 Rand McNally
Whitecap's Song Jocelyn Arundel 1962 Whittlesey House
Wildlife of Africa Jocelyn Arundel 1965 Hastings House
Wings Over the Desert Dean Graham 1945 Viking Press
Your Pony Book Hermann Wiederhold 1958 Stephen Greene Press