Jan Ješek Ptáček of Pirkštejn[a] was a Moravian noble and lord of Sloup v Čechách, Polná, and Rataje nad Sázavou.

The son of Čeněk of Oybin, Jan Ješek inherited the castles at Sloup v Čechách and Polná.

[6] It was around this time where Jan Ješek started using the name Ptáček, or "Birdie", which was continually used in his lineage.

[7] Soon after, he returned to Polná and retired from political life.

[6] Jan is mentioned in the video game Kingdom Come: Deliverance as Sir Jeschke, the father of Hans Capon.