Sammy Sosa has hit the most home runs in a month, with 20 homers in June 1998.

	NAME	HR	MONTH	G	AB	R	H	2B	3B	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Sammy Sosa S. Sosa	20	June 1998	27	114	25	34	2	0	40	6	0	27	0	2	121	96	22	0	1	0	3	.298	.331	.842	1.173
2	Giancarlo Stanton G. Stanton	18	August 2017	29	109	28	38	6	0	37	14	3	31	1	0	127	98	24	0	1	4	2	.349	.433	.899	1.332
3	Rudy York R. York	18	August 1937	30	113	27	41	5	2	50	13	0	14	1		126	104	25	0				.363	.429	.920	1.349
4	Sammy Sosa S. Sosa	17	August 2001	29	109	31	42	3	3	36	16	3	24	0	1	130	102	23	0	2	3	0	.385	.469	.936	1.405
5	Barry Bonds B. Bonds	17	May 2001	27	84	28	31	5	0	30	31	2	24	3	1	117	87	22	0	0	5	1	.369	.547	1.036	1.583
6	Albert Belle A. Belle	17	September 1995	27	97	30	30	10	0	32	13	4	13	2	1	115	91	27	0	1	1	5	.309	.409	.938	1.347
7	Willie Mays W. Mays	17	August 1965	31	113	32	41	3	0	29	17	0	19	1	1	131	95	20	1	0	3	1	.363	.446	.841	1.287
8	Rudy York R. York	17	August 1943	31	112	29	40	4	0	43	21	0	19	0		134	95	21	1			2	.357	.459	.848	1.307
9	Babe Ruth B. Ruth	17	September 1927	27	103	29	39	3	1	43	19	0	15	3		126	95	21	4				.379	.475	.922	1.398
10	Kyle Schwarber K. Schwarber	16	June 2021	27	100	22	28	0	0	30	13	1	33	0	0	116	76	16	0	2	0	3	.280	.362	.760	1.122
11	J.D. Martinez	16	September 2017	24	99	26	40	8	0	36	7	0	29	1	0	107	96	24	0	1	1	7	.404	.439	.970	1.409
12	Edwin Encarnacion E. Encarnacion	16	May 2014	30	114	26	32	5	1	33	16	0	16	1	0	130	87	22	0	0	0	4	.281	.369	.763	1.132
13	Mark McGwire M. McGwire	16	July 1999	25	88	21	26	2	0	30	22	0	21	0	0	110	76	18	0	0	4	0	.295	.436	.864	1.300
14	Albert Belle A. Belle	16	July 1998	26	101	24	41	6	0	32	9	0	13	0	0	110	95	22	0	0	2	1	.406	.455	.941	1.395
15	Mark McGwire M. McGwire	16	May 1998	26	86	25	28	2	0	32	33	0	27	0	0	119	78	18	0	0	5	0	.326	.513	.907	1.420
16	Mickey Mantle M. Mantle	16	May 1956	31	116	35	48	6	0	35	23	0	15	4	0	140	102	22	0	1	2	0	.414	.507	.879	1.386
17	Ralph Kiner R. Kiner	16	September 1949	27	92	28	30	4	1	32	28	0	10	2		120	84	21	0			4	.326	.483	.913	1.396
18	Hank Greenberg H. Greenberg	16	September 1946	27	94	26	30	4	0	39	21	0	18	0		115	82	20	0			3	.319	.443	.872	1.316
19	Shohei Ohtani S. Ohtani	15	May 2025	27	110	31	34	5	1	27	17	0	31	2	3	128	86	21	0	1	5	2	.309	.398	.782	1.180
20	Shohei Ohtani S. Ohtani	15	June 2023	27	104	27	41	7	3	29	21	0	26	4	1	126	99	25	0	1	2	2	.394	.492	.952	1.444
21	Aaron Judge A. Judge	15	September 2017	27	90	29	28	7	0	32	28	0	32	2	0	121	80	22	0	3	1	1	.311	.463	.889	1.352
22	Troy Tulowitzki T. Tulowitzki	15	September 2010	28	115	30	37	6	2	40	9	1	19	2	0	125	92	23	0	0	1	3	.322	.376	.800	1.176
23	Jim Thome J. Thome	15	June 2004	27	98	25	30	5	0	31	21	1	25	0	0	121	80	20	0	1	6	1	.306	.430	.816	1.246
24	Alex Rodriguez A. Rodriguez	15	August 2003	29	106	30	36	5	2	31	21	2	17	5	1	130	90	22	0	1	3	3	.340	.454	.849	1.303
25	Rafael Palmeiro R. Palmeiro	15	August 1999	30	110	25	35	4	1	39	14	0	17	0	0	128	86	20	0	4	1	1	.318	.383	.782	1.165