Artwork included in the monthlong angel show will be published in a "Night of 100 Angels" full-color book in spring 2012, according to a press statement.
Organizers also invited women to enter an angel costume contest, with the winner to be awarded a $500 prize.
Ten percent of proceeds from the art show and sale will be given to the Make-A-Wish Foundation of Orange County and the Inland Empire.
Planning for the event was extensive, and Whelan said the date was pushed back more than once before organizers settled on 6 p.m. Saturday.
At the event, Laguna Beach Mayor Toni Iseman will officiate at a ribbon-cutting ceremony at The Cottage Gallery. The opening festivities will continue until 10 p.m.
A procession of costumed "angels" carrying lights will wind through Laguna Beach, beginning about 8 p.m. A half an hour later, the "angels" will arrive at Whelan's North Laguna gallery for the costume judging.
Artwork will be judged by longtime Laguna artist Bob Schaar, who will also speak at the opening reception.
Whelan, a 1991 Laguna College of Art & Design graduate, is known for his classical style of illustration for magazines and books, such as "Alice in Wonderland" and the Nancy Drew series, and numerous others for major publishers. His work is included in two volumes of "The Spectrum Book of Fantastic Art."
Whelan said he hopes the angels convey a message of peace and love.
"That's what angels stand for," he said.
Both galleries will showcase the angel artwork until Sept. 20.
If You Go
What: "Night of 100 Angels"
When: 6 to 10 p.m. Saturday
Where: The Cottage Gallery, 1524 S. Coast Hwy., Laguna Beach (6 p.m. ribbon-cutting)
Whelan Galleries, 353 N. Coast Hwy. (8:30 p.m. costume judging)
Information: Call (949) 494-5076 or visit http://www.whelanartgalleries.com