The media mogul posted the snap to his Twitter page on Tuesday evening, captioning it: 'Eric has already learnt to read.'
Comedian and friend of Simon, David Walliams, was quick to retweet, writing: 'Unlike his father.'
Simon posts regular updates on Eric to his Twitter page, including snaps of him and Lauren Silverman.
The 54-year-old X Factor boss became a father for the first time in February, when his girlfriend Lauren gave birth to Eric. But to the world's surprise, Cowell seems to be revelling in fatherhood - obviously beaming with pride about his newborn.
Simon's close friend Tom Bower previously told Closer that everyone was surprised at how well their pal had embraced his new role, saying: 'Simon and Lauren are so happy. He loves the whole domestic scene, which I didn't think he would. Eric is a dream, he's a very quiet baby and there's a good atmosphere in the house. Fatherhood has really changed Simon - he's not the Cowell I knew!'
The multi-millionaire admitted he was nervous before the birth; worrying that he might not bond with his baby. But Cowell said as soon as Eric was born he just 'got it.'
We love this new soft side to Simon!