Joanna Sakowicz-Kostecka (born 1 May 1984) is a former tennis player from Poland.

As a professional, her career-high singles ranking is world No. 138, achieved on 9 October 2006. Her highest doubles ranking is world No. 312, achieved on 23 June 2003.

In her career, she won three singles titles and one doubles title on the ITF Women's Circuit.

Result	No.	Date	Tournament	Surface	Opponent	Score
Win	1.	3 June 2001	Warsaw, Poland	Clay	Raluca Ciochină	1–6, 6–2, 6–1
Loss	1.	18 November 2001	Stupava, Slovakia	Hard (i)	Petra Cetkovská	1–6, 4–6
Win	2.	30 June 2002	Rabat, Morocco	Clay	Olga Kalyuzhnaya	6–3, 7–5
Loss	2.	10 July 2005	Bella Cup, Poland	Clay	Ana Timotić	1–6, 2–6
Loss	3.	27 November 2005	Opole, Poland	Carpet	Oxana Lyubtsova	1–6, 6–3, 1–6
Win	3.	10 December 2005	Zubr Cup, Czech Republic	Carpet (i)	Lucie Hradecká	6–4, 6–4
Loss	4.	11 July 2006	Bella Cup, Poland	Clay	Andreja Klepač	0–6, 2–6

Result	No.	Date	Tournament	Surface	Partner	Opponents	Score
Win	1.	23 June 2002	Tallinn, Estonia	Clay	Petra Cetkovská	Petra Rüssegger Stefanie Weis	6–2, 4–6, 6–4
Loss	1.	5 July 2005	Bella Cup Toruń, Poland	Clay	Zuzana Hejdová	Nadejda Ostrovskaya Yevgenia Savransky	1–6, 5–7

• Joanna Sakowicz-Kostecka at the Women's Tennis Association
• Joanna Sakowicz-Kostecka at the International Tennis Federation