Charles Matthew "Chuck" Geschke (September 11, 1939 – April 16, 2021) was an American businessman and computer scientist best known for founding the graphics and publishing software company Adobe Inc. with John Warnock in 1982, with whom he also co-created the PDF document format.

[7] In 1972, he completed his PhD studies in computer science at Carnegie Mellon University under the advice of William Wulf.

[10] He hired John Warnock, and together they developed Interpress, a page description language (PDL) that could describe forms as complex as typefaces.

[14] On the morning of May 26, 1992, as Geschke was arriving for work in Mountain View, California, he was kidnapped at gunpoint from the Adobe parking lot by two men, Mouhannad Albukhari, 26, of San Jose, and Jack Sayeh, 25, of Campbell.

[17] A spokesperson for the FBI reported that the agency had monitored phone calls that the kidnappers had made to Geschke's wife, demanding a ransom.

[17] The spokesperson added that Albukhari had been arrested after he had picked up the $650,000 ransom that Geschke's daughter had left at a drop-off point.

[17] An FBI agent explained that, "[a]fter a gentlemanly discussion", Albukhari had brought them to a bungalow in Hollister, where Sayeh had been holding Geschke hostage.

[27] Geschke was a Catholic[28] and met his wife Nancy "Nan" McDonough at a religious conference on social action in the spring of 1961.

[32] Geschke's father helped during the early days of Adobe by checking color separation work with his engraver's loupe.

Geschke described his father's acknowledgment of the high quality of the halftone patterns as "a wonderful moment".