Don Budge defeated Gene Mako in the final, 6–3, 6–8, 6–2, 6–1 to win the men's singles tennis title at the 1938 U.S. National Championships. He became the first player in tennis history to complete the Grand Slam.^[2]

The tournament used two lists of eight players for seeding the men's singles event; one for U.S. players and one for foreign players. Don Budge is the champion; others show the round in which they were eliminated.^[2]

• Q = Qualifier
• WC = Wild card
• LL = Lucky loser
• r = Retired

	Quarterfinals									Semifinals									Final
	1	Don Budge	6	6	6
		Harry Hopman	3	1	3
										1	Don Budge	6	6	6
										7	Sidney Wood	3	3	3
	7	Sidney Wood	6	6	6
	15	Bryan Grant	2	3	2
																			1	Don Budge	6	6	6	6
																				Gene Mako	3	8	2	1
		Gilbert Hunt	5	6	6	0
		Gene Mako	7	1	8	6
											Gene Mako	6	7	6
										1	John Bromwich	3	5	4
	5	Joseph Hunt	1	11	3	4
	1	John Bromwich	6	9	6	6

	First round									Second round									Third round									Fourth round
										1	Budge	6	6	6
											Van Horn	0	0	1
																			1	Budge	6	7	9
																				Kamrath	3	5	7
											Kamrath	6	6	6
											Kramer	1	0	1
																												1	Budge	6	6	6
																												15	Hare	3	4	0
											Finnigan	7	0	4	4
											Farrell	5	6	6	6
																				Farrell	3	2	1
																			15	Hare	6	6	6
											Schwartz	4	5	12	7	8
										15	Hare	6	7	10	5	10

	First round									Second round									Third round									Fourth round
										9	Cooke	6	7	6
											Godsell	2	5	0
																			9	Cooke	2	6	4	8
																				Hopman	6	4	6	10
											Hopman	6	7	6
											Buxby	3	5	4
																													Hopman	6	6	7
																													McNeill	4	3	5
											McCauliff	2	r
											Toley	4
																				Toley	1	4	1
		Hartman	7	4	6	6														McNeill	6	6	6
		Lowman	5	6	2	3					Hartman	5	3	1
		McNeill	6	4	6	6					McNeill	7	6	6
	7	Destremau	2	6	1	3

	First round									Second round									Third round									Fourth round
	7	Wood	6	6	6
		McGehee	4	1	4					7	Wood	9	4	1	6	6
		Hall	6	8	6						Hall	7	6	6	4	4
		Davenport	1	6	4														7	Wood	6	6	4	6	6
		Mulloy	7	6	6															Mulloy	4	1	6	8	2
		Lewis	5	1	4						Mulloy	7	6	6
		Low	6	6	6						Low	5	3	1
		Lay	2	0	0																							7	Wood	8	6	6
		Gillespie	6	4	2	6	6																					11	Kukuljević	6	4	3
		Bushman	4	6	6	4	4				Gillespie	6	2	6	2	6
		Robertson	6	4	7	6					Robertson	3	6	0	6	3
		Lavine	4	6	5	3														Gillespie	2	2	1
		Surface	6	6	6														11	Kukuljević	6	6	6
		Brugnon	1	1	2						Surface	1	3	1
	11	Kukuljević	7	6	6					11	Kukuljević	6	6	6
		Prochaska	5	1	0

	First round									Second round									Third round									Fourth round
	15	Grant	6	9	6
		Everett	4	7	4					15	Grant	6	6	6
		Mattmann									Mattmann	2	2	2
		Harman	w/o																15	Grant	6	6	4	6
		Henderson	6	6	5	9														Anderson	3	1	6	1
		Bowden	3	4	7	7					Henderson	1	3	6
		Anderson	6	6	4	6					Anderson	6	6	8
		Rood	4	4	6	2																						15	Grant	6	4	6	7
		Bellis	3	4	6	6	7																					3	Quist	1	6	1	5
		Anderson	6	6	4	0	5				Bellis	6	11	2
		Ballagh	6	7	6						Ballagh	8	13	6
		Burt	2	5	2															Ballagh	6	2	4	4
		Umstaedter	6	6	5	6													3	Quist	3	6	6	6
		Johnson	4	4	7	2					Umstaedter	3	1	0
	3	Quist	6	6	6					3	Quist	6	6	6
		Broida	2	1	1

	First round									Second round									Third round									Fourth round
	3	Riggs	5	6	6	6
		Lauck	7	3	4	4				3	Riggs	5	6	6	6
		Guernsey	6	6	6						Guernsey	7	2	3	4
		Lubin	2	1	3														3	Riggs	6	6	4	1	6
		Shayes	6	6	6															Shayes	3	3	6	6	4
		Mouvet	4	1	2						Shayes	6	4	6	6
		Bobbitt	6	6	6						Bobbitt	3	6	4	4
		De Gray	2	4	4																							3	Riggs	2	6	7	6	4
		Jarvis	6	4	6	6																							Hunt	6	0	9	0	6
		Abrams	1	6	3	1					Jarvis	4	3	6	6	6
		Talbert	6	6	6						Talbert	6	6	4	2	2
		Baldwin	1	3	3															Jarvis	3	2	2
		Hunt	6	4	6	5	6													Hunt	6	6	6
		Murphy	4	6	4	7	4				Hunt	6	1	6	6	6
	13	Nakano	3	6	3	6	6			13	Nakano	8	6	3	3	3
		Wetherell	6	3	6	2	2

	First round									Second round									Third round									Fourth round
	11	Kovacs	6	6	9
		Filby	1	3	7					11	Kovacs	6	4	3	6	7
		Kuramitsu	7	3	6	6					Kuramitsu	3	6	6	4	5
		Hughes	5	6	2	2													11	Kovacs	0	2	6
		Mako	6	6	6															Mako	6	6	8
		Podesta	1	2	2						Mako	6	6	18
		Foreman									Foreman	2	1	16
		Stephens	w/o																										Mako	6	6	9
		Weston	6	6	7	5	8																					5	Punčec	2	4	7
		Mangin	1	4	9	7	6				Weston	6	6	4	7
		Lynch	6	6	6						Lynch	4	3	6	5
		Freisenbruch	0	1	3															Weston	0	2	2
		Kerdasha	6	6	6														5	Punčec	6	6	6
		Lanas	0	2	1						Kerdasha	2	0	2
	5	Punčec	6	4	6	6				5	Punčec	6	6	6
		Du Rivage	1	6	1	4

	First round									Second round									Third round									Fourth round
	5	Hunt	6	4	6	6
		Abe	1	6	1	3				5	Hunt	6	8	6
											Sabin	1	6	3
																			5	Hunt	6	6	6
																				Dunn	2	3	4
											Steele Jr.	2	3	4
											Dunn	6	6	6
																												5	Hunt	6	4	6	9
																												9	Petra	4	6	4	7
											Murphy	3	6	6	5	4
											Fishbach	6	4	4	7	6
																				Fishbach	2	4	3
																			9	Petra	6	6	6
											Swanson	4	5	1
										9	Petra	6	7	6

	First round									Second round									Third round									Fourth round
										13	Parker	6	6	6
											Lurie	2	1	3
																			13	Parker	6	6	7
																				Rood	2	4	5
											Hawley	4	2	8
											Rood	6	6	10
																												13	Parker	2	3	2
																												1	Bromwich	6	6	6
											Shields	6	6	8
											Sutter	3	3	6
																				Shields	6	12	8	2	2
																			1	Bromwich	1	10	10	6	6
											Ganzenmuller	1	0	1
										1	Bromwich	6	6	6

• 1938 U.S. National Championships on ITFtennis.com Archived 2016-03-31 at the Wayback Machine, the source for this draw