Christian Frederik Bayer (6 July 1841 – 22 November 1933) was a Danish illustrator.

He is remembered for his topographical drawings and watercolours from Copenhagen, many of which were featured on postcards.

He also trained for half a year in Henneberg and Rosenstand's xylographic workshop and in 1863 while studying painting under Johannes Exner.

He created a vast number of topographical drawings and watercolours from Copenhagen, Many of them featured celebrities.

Bayer's works were for instance featured on a series of 32 postcards from Alex.