Kajetan Duszyński (Polish pronunciation: [kaˈjɛtan duˈʂɨj̃skʲi]; born 12 May 1995) is a Polish sprinter specialising in the 400 metres.^[2] He represented his country in the 4 × 400 metres relay at the 2017 World Championships reaching the final, as well in the mixed 4 x 400 metres relay at the 2020 Summer Olympics where Poland won gold medal.

Year	Competition	Venue	Position	Event	Notes
Representing  Poland
2014	World Junior Championships	Eugene, United States	13th (h)	4 x 400 m relay	3:10.94
2015	European U23 Championships	Tallinn, Estonia	14th (h)	400 m	46.89
			2nd	4 x 400 m relay	3:05.35
2017	European U23 Championships	Bydgoszcz, Poland	7th	400 m	46.80
			2nd	4 x 400 m relay	3:04.22
	World Championships	London, United Kingdom	7th	4 × 400 m relay	3:01.59
	Universiade	Taipei, Taiwan	4th	400 m	46.50
2018
	European Championships	Berlin, Germany	5th	4 × 400 m relay	3:02.27
2019	World Relays	Yokohama, Japan	7th (B)	4 × 400 m relay	3:05.91
	Universiade	Naples, Italy	3rd	4 × 400 m relay	3:03.35
2021	European Indoor Championships	Toruń, Poland	12th (sf)	400 m	47.26
	World Relays	Chorzów, Poland	9th (h)	4 × 400 m relay	3:05.04
	Olympic Games	Tokyo, Japan	5th	4 × 400 m relay	2:58.46
			1st	4 × 400 m mixed relay	3:09.87 OR
2022	World Indoor Championships	Belgrade, Serbia	11th (sf)	400 m	47.21
			4th	4 × 400 m relay	3:07.81
	World Championships	Eugene, United States	32nd (h)	400 m	46.57
			9th	4 × 400 m relay	3:02.51
2023	European Indoor Championships	Istanbul, Turkey	10th (sf)	400 m	47.01
2024	European Championships	Rome, Italy	–	4 × 400 m relay	DQ
	Olympic Games	Paris, France	12th (h)	4 × 400 m relay	3:01.21

^[3]

Outdoor

• 200 metres – 22.02 (-0.3 m/s, Łódź 2017)
• 400 metres – 44.92 (Bern 2021)

Indoor

• 400 metres – 47.84 (Spała 2016)

• Kajetan Duszyński at World Athletics
• Kajetan Duszyński at European Athletics
• Kajetan Duszyński at Olympedia
• Kajetan Duszyński at the Paris 2024 Summer Olympics
• Kajetan Duszyński at Olympics.com
• Kajetan Duszyński at the Polski Komitet Olimpijski (in Polish)
• Kajetan Duszyński at the Polski Związek Lekkiej Atletyki (in Polish)