Singles
2004 Gerry Weber Open
Final
Champion	Roger Federer
Runner-up	Mardy Fish
Score	6–0, 6–3
Details
Draw	32
Seeds	8
Events
Singles Doubles
← 2003 · Gerry Weber Open · 2005 →

Roger Federer was the defending champion, and won in the final 6–0, 6–3 against Mardy Fish.^[1] It was his second singles title in Halle. He did not lose a single set in the entire tournament.

A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.

	Semifinals							Final
	1	Roger Federer	6	6
	3	Jiří Novák	3	4
								1	Roger Federer	6	6
								6	Mardy Fish	0	3
	6	Mardy Fish	6	4	77
	2	Rainer Schüttler	4	6	64

	First round							Second round							Quarterfinals							Semifinals
	1	R Federer	6	6
		T Johansson	3	2				1	R Federer	6	6
		F Mayer	77	2	62				M Youzhny	2	1
		M Youzhny	64	6	77										1	R Federer	6	7
	WC	A Waske	1	4												A Clément	3	5
		A Clément	6	6					A Clément	77	6
		A Popp	1	6	6				A Popp	64	2
	7	A Pavel	6	4	4																	1	R Federer	6	6
	3	J Novák	6	6																		3	J Novák	3	4
		I Ljubičić	2	2				3	J Novák	6	6
	Q	M Kratochvil	2	2				LL	M Chiudinelli	3	1
	LL	M Chiudinelli	6	6											3	J Novák	6	77
		K Carlsen	3	77	7										WC	T Haas	4	61
	Q	M Berrer	6	65	5				K Carlsen	77	2	4
	WC	T Haas	6	6				WC	T Haas	63	6	6
	8	F López	3	4

	First round							Second round							Quarterfinals							Semifinals
	6	M Fish	6	6
	WC	D Prinosil	4	2				6	M Fish	6	6
		F Volandri	6	2	2				S Sargsian	4	3
		S Sargsian	2	6	6										6	M Fish	6	6
	Q	A Seppi	77	2	6											F Verdasco	2	2
		N Davydenko	65	6	3			Q	A Seppi	3	4
		F Verdasco	7	7					F Verdasco	6	6
	4	M Verkerk	5	5																		6	M Fish	6	4	77
	5	M Safin	2	77	64																	2	R Schüttler	4	6	64
		J Björkman	6	63	77				J Björkman	7	4	4
		L Burgsmüller	3	4					N Kiefer	5	6	6
		N Kiefer	6	6												N Kiefer	3	62
		J Johansson	77	4	6										2	R Schüttler	6	77
		R Söderling	63	6	3				J Johansson	65	4
	Q	J Hernych	3	2				2	R Schüttler	77	6
	2	R Schüttler	6	6

• Singles Draw
• Qualifying Draw