Justine Henin-Hardenne defeated Nadia Petrova in the final, 6–3, 4–6, 6–3 to win the singles tennis title at the 2005 WTA German Open.

Amélie Mauresmo was the defending champion, but lost in the quarterfinals to Petrova.

	Quarterfinals							Semifinals							Finals
	1	Maria Sharapova	2	4
	12	Justine Henin-Hardenne	6	6
								12	Justine Henin-Hardenne	6	6
								7	Patty Schnyder	0	1
	4	Svetlana Kuznetsova	2	2
	7	Patty Schnyder	6	6
															12	Justine Henin-Hardenne	6	4	6
															6	Nadia Petrova	3	6	3
	8	Elena Bovina	3	6	3
	13	Jelena Janković	6	3	6
								13	Jelena Janković	4	7	3
								6	Nadia Petrova	6	65	6
	6	Nadia Petrova	6	6
	2	Amélie Mauresmo	2	3

	First round							Second round							Third round							Quarterfinals
								1	M Sharapova	6	6
		AL Grönefeld	6	6					AL Grönefeld	2	2
		E Linetskaya	1	2											1	M Sharapova	6	6
		A Jidkova	3	1												S Peng	2	1
		M Vento-Kabchi	6	6					M Vento-Kabchi	1	2
		S Peng	7	6					S Peng	6	6
	14	A Sugiyama	5	4																		1	M Sharapova	4	2
	12	J Henin-Hardenne	7	4	6																	12	J Henin-Hardenne	6	6
		I Benešová	5	6	1			12	J Henin-Hardenne	2	6	6
		F Zuluaga	3	1					M Kirilenko	6	1	3
		M Kirilenko	6	6											12	J Henin-Hardenne	4	6	6
	Q	K Peschke	6	7											Q	K Peschke	6	4	2
	LL	A Haynes	2	64				Q	K Peschke	6	6
								5	V Zvonareva	2	0

	First round							Second round							Third round							Quarterfinals
								4	S Kuznetsova	6	6
		M Maleeva	6	6					M Maleeva	2	1
		V Dushevina	3	1											4	S Kuznetsova	5	6	6
	Q	M Müller	0	65												C Martínez	7	4	4
		C Martínez	6	7					C Martínez	6	6
		G Dulko	6	6					G Dulko	1	3
	15	D Hantuchová	4	4																		4	S Kuznetsova	2	2
	11	K Clijsters	6	6																		7	P Schnyder	6	6
	Q	Y Fedak	1	0				11	K Clijsters	7	6
		D Safina	6	6					D Safina	5	2
		A Ivanovic	1	4											11	K Clijsters	7	5r
	Q	T Panova	64	2											7	P Schnyder	64	6
		A Medina Garrigues	7	6					A Medina Garrigues	62	4
								7	P Schnyder	7	6

	First round							Second round							Third round							Quarterfinals
								8	E Bovina	7	5	6
	Q	K Böhmová	7	3	65				E Daniilidou	5	7	1
		E Daniilidou	65	6	7										8	E Bovina	6	6
		M Shaughnessy	4	6	7											M Shaughnessy	4	2
	Q	L Průšová	6	3	60				M Shaughnessy	7	6
		D Randriantefy	7	6					D Randriantefy	5	3
	9	N Dechy	5	1																		8	E Bovina	3	6	3
	13	J Janković	6	6																		13	J Janković	6	3	6
	Q	T Obziler	3	3				13	J Janković	2	6	7
	WC	A Barna	1	2					F Pennetta	6	4	61
		F Pennetta	6	6											13	J Janković	6	6
		D Chládková	6	5	4										WC	J Schruff	3	2
	WC	J Schruff	3	7	6			WC	J Schruff	6	1	6
								3	A Myskina	2	6	4

	First round							Second round							Third round							Quarterfinals
								6	N Petrova	7	6
		M Marrero	4	1					K Koukalová	5	4
		K Koukalová	6	6											6	N Petrova	6	7
		A Chakvetadze	4	3												M Pierce	2	5
		M Pierce	6	6					M Pierce	6	6
	WC	S Klösel	5	60				10	E Likhovtseva	2	2
	10	E Likhovtseva	7	7																		6	N Petrova	6	6
	16	K Šprem	6	1	2																	2	A Mauresmo	2	3
		V Razzano	4	6	6				V Razzano	7	3	7
		J Craybas	4	6	6				J Craybas	68	6	5
	Q	S Gehrlein	6	3	4											V Razzano	4	2
		A Smashnova	6	6											2	A Mauresmo	6	6
		J Kostanić	3	2					A Smashnova	4	1
								2	A Mauresmo	6	6

• Main draw