Singles
1998 Waldbaum's Hamlet Cup
1997 Champion	Carlos Moyá
Final
Champion	Patrick Rafter[1]
Runner-up	Felix Mantilla
Score	7–6(7–3), 6–2
Details
Draw	32
Seeds	8
Events
Singles Doubles
← 1997 · Waldbaum's Hamlet Cup · 1999 →

The 1998 Waldbaum's Hamlet Cup was a men's tennis tournament played on Hard courts in Long Island, United States that was part of the International Series of the 1998 ATP Tour. It was the eighteenth edition of the tournament and was held from 24 to 30 August 1998.

Champion seeds are indicated in bold text while text in italics indicates the round in which those seeds were eliminated.

	Semifinals							Final[1]
	8	Felix Mantilla	6	5	6
		Marat Safin	3	7	4
								8	Felix Mantilla	63	2
								2	Patrick Rafter	7	6
	4	Greg Rusedski	4	5
	2	Patrick Rafter	6	7

	First round							Second round							Quarterfinals							Semifinals
		G Kuerten	6	7
	1	M Ríos	3	64					G Kuerten	2	6	7
		F Clavet	6	6					F Clavet	6	3	68
		L Mor	2	1												G Kuerten	4	6	6
		B Ulihrach	6	7											8	F Mantilla	6	2	4
		C Doseděl	4	65					B Ulihrach	64	3
	8	F Mantilla	6	6				8	F Mantilla	7	6
		S Bruguera	4	4																		8	F Mantilla	6	5	6
	3	C Moyá	7	6																			M Safin	3	7	4
		B Steven	5	3				3	C Moyá	2	2
		D Prinosil	0	6	6				D Prinosil	6	6
		D Hrbatý	6	3	1											D Prinosil	1	62
		F Dewulf	6	7												M Safin	6	7
		M Woodforde	4	66					F Dewulf	66	1
		M Safin	6	6					M Safin	7	6
	6	A Berasategui	3	2

	First round							Second round							Quarterfinals							Semifinals
	9	J Siemerink	4	6	6
		J Alonso	6	1	4			9	J Siemerink	1	6	3
		D Vacek	6	6					D Vacek	6	4	6
		M Rosset	1	4												D Vacek	2	3
		F Meligeni	62	6	6										4	G Rusedski	6	6
		G Raoux	7	4	3				F Meligeni	2	66
	4	G Rusedski	6	6				4	G Rusedski	6	7
		M Norman	3	4																		4	G Rusedski	4	5
		H Arazi	5	6	7																	2	P Rafter	6	7
	7	G Ivanišević	7	3	62				H Arazi	3	6	3
		N Escudé	6	6					N Escudé	6	3	6
		T Johansson	1	4												N Escudé	3	2
		M Damm	3	6	6										2	P Rafter	6	6
		J Burillo	6	2	3				M Damm	4	3
	2	P Rafter	6	4	6			2	P Rafter	6	6
		J Sánchez	2	6	4