Defending champion René Lacoste defeated Bill Tilden in the final, 11–9, 6–3, 11–9 to win the men's singles tennis title at the 1927 U.S. National Championships.^[2] It was Lacoste's second U.S. Championships singles title and fifth major singles title overall.^[3]

The tournament used two lists of eight players for seeding the men's singles event; one list of U.S. players and one for foreign players. René Lacoste is the champion; others show in brackets the round in which they were eliminated.

	Quarterfinals									Semifinals									Final
		Bill Tilden	6	3	10	6
		Jean Borotra	1	6	8	1
											Bill Tilden	14	6	4	9
											Frank Hunter	12	1	6	7
		Frank Hunter	4	5	6	6	6
		John Hennessey	6	7	0	3	4
																				Bill Tilden	9	3	9
																				René Lacoste	11	6	11
		Bill Johnston	3	6	6	6
		Jacques Brugnon	6	2	4	4
											Bill Johnston	2	6	4	1
											René Lacoste	6	2	6	6
		Manuel Alonso	2	6	4	1
		René Lacoste	6	2	6	6

	First round									Second round									Third round									Quarterfinals
	1	Tilden	6	10	7
		Mercur	3	8	5					1	Tilden	6	6	6
	Hyde		w/	o							Bell	2	2	2
	Bell																		1	Tilden	4	6	11	6
	Griffin		3	8	6	6														Griffin	6	1	9	0
	Hubbell		6	6	4	4					Griffin	6	6	6
		Griffin	6	5	2	6	3			(7)	Ohta	0	2	2
	(7)	Ohta	2	7	6	3	6																					1	Tilden	6	3	10	6
	8	Doeg	8	3	6	2																						(3)	Borotra	1	6	8	1
		Appel	10	6	3	6				Appel		6	5	0
	Lang		6	4	4	6	6			Lang		8	7	6
	Anderson		1	6	6	0	3													Lang	6	6	3	1	3
	Gilpin		5	3	6														(3)	Borotra	2	4	6	6	6
	Thalheimer		7	6	3	rtd.					Gilpin	4	6	8	5
		Toba	6	6	2	3	0			(3)	Borotra	6	8	6	7
	(3)	Borotra	3	2	6	6	6

	First round									Second round									Third round									Quarterfinals
	4	Hunter	6	8	3	6
		Seligson	1	6	6	2				4	Hunter	6	9	6
	Chandler										Chandler	2	7	4
	Allison		w/	o															4	Hunter	7	6	6
	Evans		0	1	1														(5)	Washer	5	3	3
	Coggeshall		6	6	6						Coggeshall	4	0	2
		Coen	w/	o						(5)	Washer	6	6	6
	(5)	Washer																										4	Hunter	4	5	6	6	6
	6	Williams	w/	o																									Hennessey	6	7	0	3	4
		Herndon								Herndon		4	1	2
	Baur		3	4	2					Hennessey		6	6	6
	Hennessey		6	6	6															Hennessey	6	6	4	3	6
	Feibleman		6	6	6														(2)	Cochet	4	4	6	6	1
	Onda		4	3	4						Feibleman	4	6	7	0
		Kynaston	3	5	3					(2)	Cochet	6	8	5	6
	(2)	Cochet	6	7	6

	First round									Second round									Third round									Quarterfinals
	2	Johnston	7	6	7
		King	5	3	5					2	Johnston	6	6	7
	Olhausen		6	7	4						Marsh	1	4	5
	Marsh		8	9	6														2	Johnston	6	6	6
	Williams		w/	o															(6)	Wright	4	4	4
	Leslie										Leslie	5	1	9	1
		Mooney	0	4	2					(6)	Wright	7	6	7	6
	(6)	Wright	6	6	6																							2	Johnston	3	6	6	6
	7	White	7	3	1	0																						(4)	Brugnon	6	2	4	4
		Jones	5	6	6	6				Jones		6	6	6
	Fischer		6	3	6	6	6			Fischer		1	1	2
	Shields		3	6	2	8	3													Jones	7	6	6	1	1
	Strachan		4	6	6	6													(4)	Brugnon	9	4	3	6	6
	Wood		6	3	4	2					Strachan	0	1	2
		Mangin	4	5	3					(4)	Brugnon	6	6	6
	(4)	Brugnon	6	7	6

	First round									Second round									Third round									Quarterfinals
	3	Alonso	5	8	6	6
		Hall	7	6	4	3				3	Alonso	6	4	6	6
	Washburn		5	6	5	6	6				Washburn	2	6	3	2
	Weiner		7	1	7	0	0												3	Alonso	5	3	6	6	6
	Van Ryn		6	6	3	6														Van Ryn	7	6	1	4	0
	Johnson		4	4	6	4				Van Ryn		4	6	7	8
		Bowman	6	6	6					Bowman		6	2	5	6
	(8)	Miki	4	1	2																							3	Alonso	8	4	1	2
	5	Lott	w/	o																								(1)	Lacoste	6	6	6	6
		Behr								Behr		3	3	2
	Harada		6	6	6					Harada		6	6	6
	Orser		1	3	1															Harada	3	4	3
	Nunns		4	6	3	6	6												(1)	Lacoste	6	6	6
	Sullivan		6	4	6	0	3				Nunns	0	2	4
		Owens	4	4	2					(1)	Lacoste	6	6	6
	(1)	Lacoste	6	6	6