Heide Seyerling (born 19 August 1976) is a former South African athlete, born in Port Elizabeth, specializing in the 200 and 400 metres. She twice competed at the Olympic Games, in 2000 and 2004. At the 2000 Games she reached the 400 metres final finishing 6th with a new (and still standing now) national record of 50.05. She is married to former sprinter Mathew Quinn.

Year	Competition	Venue	Position	Event	Notes
Representing  South Africa
1994	African Junior Championships	Algiers, Algeria	2nd	100 m	11.69
			1st	200 m	23.59
			2nd	4 × 100 m relay	46.15
	World Junior Championships	Lisbon, Portugal	10th (sf)	100m	11.62 (wind: +0.8 m/s)
			1st	200m	22.80 w (wind: +2.2 m/s)
			2nd (h)[1]	4 × 100 m relay	45.63
1995	World Championships	Gothenburg, Sweden	–	200 m	DQ
1998	African Championships	Dakar, Senegal	3rd	200 m	22.89
	Commonwealth Games	Kuala Lumpur, Malaysia	5th	200 m	23.07
1999	World Championships	Edmonton, Canada	38th (h)	200 m	23.59
			11th (h)	4 × 100 m relay	44.35
	All-Africa Games	Johannesburg, South Africa	5th (h)	200 m	23.31[2]
			7th	400 m	52.27
2000	Olympic Games	Sydney, Australia	6th	400 m	50.05 (NR)
2001	World Championships	Edmonton, Canada	9th (sf)	400 m	50.87
2002	Commonwealth Games	Manchester, United Kingdom	5th	400 m	52.87
	African Championships	Radès, Tunisia	6th (h)	400 m	53.81[3]
2003	World Championships	Paris, France	20th (sf)	400 m	51.89
	All-Africa Games	Abuja, Nigeria	6th	400 m	52.45
			2nd	4 × 100 m relay	44.44
2004	African Championships	Brazzaville, Republic of the Congo	5th	400 m	51.67
			2nd	4 × 100 m relay	44.42
			2nd	4 × 400 m relay	3:30.12
	Olympic Games	Athens, Greece	37th (h)	200 m	23.66
2006	African Championships	Bambous, Mauritius	4th	400 m	53.26
			1st	4 × 400 m relay	3:36.88

• 100 m – 11.35 (-0.3) (Durban 1999)
• 200 m – 22.63 (+1.8) (Durban 2001)
• 400 m – 50.05 (Sydney 2000)

• IAAF profile