Mark McGwire has launched the most homers by a first baseman in a season, with 70 home runs in 1998.

	NAME	HR	SEASON	TM	G	AB	R	H	2B	3B	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS	WRC	WRAA	WOBA	WRC+	BRAA
1	Mark McGwire M. McGwire	70	1998	STL	155	509	130	152	21	0	147	162	6	155	1	0	681	383	91	0	4	28	8	.299	.470	.752	1.222	176	91.7	.492	205	90.7
2	Mark McGwire M. McGwire	65	1999	STL	153	521	118	145	21	1	147	133	2	141	0	0	661	363	87	0	5	21	12	.278	.424	.697	1.120	150	64.2	.453	169	61.5
3	Ryan Howard R. Howard	58	2006	PHI	159	581	104	182	25	1	149	108	9	181	0	0	704	383	84	0	6	37	7	.313	.425	.659	1.084	151	63	.436	162	57.5
4	Mark McGwire M. McGwire	58	1997	TOT	156	540	86	148	27	0	123	101	9	159	3	0	657	349	85	0	7	16	9	.274	.393	.646	1.039	134	52.9	.429	161	51.4
5	Hank Greenberg H. Greenberg	58	1938	DET	155	556	143	175	23	4	147	119	3	92	7	5	681	380	85	3				.315	.438	.683	1.122	166	80.3	.489	162	62
6	Jimmie Foxx J. Foxx	58	1932	PHA	154	585	151	213	33	9	169	116	0	96	3	7	701	438	100	0				.364	.469	.749	1.218	193	105.6	.522	198	95.8
7	Matt Olson M. Olson	54	2023	ATL	162	608	127	172	27	3	139	104	4	167	1	0	720	367	84	0	4	8	13	.283	.389	.604	.993	144	56.4	.413	161	54.1
8	Pete Alonso P. Alonso	53	2019	NYM	161	597	103	155	30	2	120	72	21	183	1	0	693	348	85	0	3	6	13	.260	.358	.583	.941	126	38.4	.384	144	40.3
9	Chris Davis C. Davis	53	2013	BAL	160	584	103	167	42	1	138	72	10	199	4	1	673	370	96	0	7	12	4	.286	.370	.634	1.004	130	56.3	.421	167	51.4
10	Jim Thome J. Thome	52	2002	CLE	147	480	101	146	19	2	118	122	5	139	1	2	613	325	73	0	6	18	5	.304	.445	.677	1.122	142	68.3	.461	189	67.1
11	Mark McGwire M. McGwire	52	1996	OAK	130	423	104	132	21	0	113	116	8	112	0	0	548	309	73	0	1	16	14	.312	.467	.730	1.198	142	71.8	.489	190	68.5
12	Cecil Fielder C. Fielder	51	1990	DET	159	573	104	159	25	1	132	90	5	182	0	1	673	339	77	0	5	11	15	.277	.377	.592	.969	127	51.8	.419	165	50.2
13	Johnny Mize J. Mize	51	1947	NYG	154	586	137	177	26	2	138	74	4	42	2		664	360	79	0			6	.302	.384	.614	.998	132	57.1	.448	156	47.4
14	Prince Fielder P. Fielder	50	2007	MIL	158	573	109	165	35	2	119	90	14	121	2	2	681	354	87	0	4	21	9	.288	.395	.618	1.013	134	50.1	.419	153	46.7
15	Jimmie Foxx J. Foxx	50	1938	BSA	149	565	139	197	33	9	175	119	0	76	5	4	685	398	92	1				.349	.462	.704	1.166	178	91.7	.508	173	74.2
16	Albert Pujols A. Pujols	49	2006	STL	143	535	119	177	33	1	137	92	4	50	7	2	634	359	83	0	3	28	20	.331	.431	.671	1.102	142	62.6	.447	174	61.7
17	Todd Helton T. Helton	49	2001	COL	159	587	132	197	54	2	146	98	5	104	7	5	696	402	105	1	5	15	14	.336	.432	.685	1.116	163	76.6	.457	160	54.8
18	Jim Thome J. Thome	49	2001	CLE	156	526	101	153	26	1	124	111	4	185	0	1	644	328	76	0	3	14	9	.291	.416	.624	1.040	136	55.7	.429	167	54.4
19	Mark McGwire M. McGwire	49	1987	OAK	151	557	97	161	28	4	118	71	5	131	1	1	641	344	81	0	8	8	6	.289	.370	.618	.987	124	45.2	.411	157	46.2
20	Ted Kluszewski T. Kluszewski	49	1954	CIN	149	573	104	187	28	3	141	78	3	35	0	2	659	368	80	0	5		12	.326	.407	.642	1.049	140	65.5	.461	164	54
21	Lou Gehrig L. Gehrig	49	1936	NYY	155	579	167	205	37	7	152	130	7	46	3	4	719	403	93	3				.354	.478	.696	1.174	192	97.6	.512	178	85.8
22	Lou Gehrig L. Gehrig	49	1934	NYY	154	579	128	210	40	6	166	109	2	31	9	5	690	409	95	0				.363	.465	.706	1.172	182	94.8	.511	194	90.9
23	Vladimir Guerrero Jr. V. Guerrero Jr.	48	2021	TOR	161	604	123	188	29	1	111	86	6	110	4	1	698	363	78	0	2	7	20	.311	.401	.601	1.002	145	60.4	.419	166	56.1
24	Ryan Howard R. Howard	48	2008	PHI	162	610	105	153	26	4	146	81	3	199	1	1	700	331	78	0	6	17	11	.251	.339	.543	.881	107	22.6	.368	121	18.2
25	Jimmie Foxx J. Foxx	48	1933	PHA	149	573	125	204	37	9	163	96	1	93	2	2	670	403	94	0				.356	.449	.703	1.153	170	92.1	.510	189	79.8