|Born||March 23, 1993,|
|6 ft 2 in (1.88 m)|
198 lb (90 kg; 14 st 2 lb)
|Tipsport Extraliga team
|BK Mladá Boleslav|
HC Zubr Přerov
Aukro Berani Zlín
HC Zubr Přerov
|Ntl. team||Czech Republic|
Šťastný began his junior career with the HC Přerov organisation. He made his senior debut in the 2011-12 season playing 5 games with the HC Zubr Přerov of the 2. Liga while also playing 39 games with the HC Přerov junior team. In the 2012-13 season, he played with the HC Olomouc junior team. In 2013, Šťastný returned to the HC Přerov organisation and finished there his junior career playing 6 games with the HC Přerov junior team and 42 regular season games and 13 play-off games with the HC Zubr Přerov of the 2. Liga in the 2013-14 season.
In the 2014-15 season, Šťastný played 26 regular season games, 12 play-off games and 4 1. Liga qualification games with the HC Zubr Přerov which gained promotion to the 1. Liga for the next season. He also played 25 games on loan with the PSG Zlín of the Tipsport Extraliga.
In the next season, Šťastný played 26 games with the HC Zubr Přerov of the WSM Liga (formerly 1. Liga) and 29 regular season games and 9 play-off games on loan with the PSG Zlín of the Tipsport Extraliga.
Šťastný began the 2016-17 season with the HC Zubr Přerov of the WSM Liga but after 3 games played, he moved definitely to the PSG Zlín of the Tipsport Extraliga. In this season, he played there 43 games.
He continued with the Aukro Berani Zlín (formerly PSG Zlín) of the Tipsport Extraliga in the next season.
Since 2018, Šťastný plays with the BK Mladá Boleslav of the Tipsport Extraliga. He is signed there until the end of the 2022-23 season.