The Little Britain comedian recorded a video message for youngsters at Marches Academy Trust schools after hearing they have been enjoying his books.
Many students chose Walliams' books as a gift from the Trust when they moved to one of its secondary schools.
In the light-hearted message, Walliams said: "I hope you're all getting through lockdown OK.
"I hope you're all staying safe and, most importantly, I hope you're all reading my books and watching Britain's Got Talent.
"But you don't have to watch the acts - you can just fast forward and watch my bits.
"Take care everybody."
Walliams books include the popular Gangsta Granny, Billionaire Boy and The World's Worst Children.
Marches Academy Trust is made up of nine schools including The Marches School and Sixth Form in Oswestry; Sir John Talbot’s School and Sixth Form in Whitchurch; Lower Heath CE Primary School and Nursery; Tilstock CofE Primary School and Nursery; Grove School and Sixth Form in Market Drayton; Shrewsbury Academy in Shrewsbury; Longlands Community Primary School in Market Drayton; The Grange Primary School and Oakmeadow Primary School and Nursery, both in Shrewsbury.
Hayley Alldridge, head of marketing and brand at Marches Academy Trust, said: “Our students and staff are working incredibly hard especially in these difficult times so we contacted David to see if he’d send a special message to our school communities.”