Since 1930, Barry Bonds has the highest on-base percentage in a season, with an on-base percentage of .609 in 2004.

Interpreted as:

highest obp with a minimum of 3.1 PA per team game by a player in a season since 1930

	NAME	OBP	SEASON	TM	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	SLG	OPS	WRC	WRAA	WOBA	WRC+	BRAA
1	Barry Bonds B. Bonds	.609	2004	SFG	147	373	129	135	27	3	45	101	232	9	41	6	1	617	303	75	0	3	120	5	.362	.812	1.422	185	108	.537	233	105.7
2	Barry Bonds B. Bonds	.582	2002	SFG	143	403	117	149	31	2	46	110	198	9	47	9	2	612	322	79	0	2	68	4	.370	.799	1.381	183	110	.544	244	109.9
3	Ted Williams T. Williams	.553	1941	BSA	143	456	135	185	33	3	37	120	147	3	27	2	4	606	335	73	0			10	.406	.735	1.287	179	108.8	.568	221	96.9
4	Barry Bonds B. Bonds	.529	2003	SFG	130	390	111	133	22	1	45	90	148	10	58	7	0	550	292	68	0	2	61	7	.341	.749	1.278	148	80.5	.503	212	79.4
5	Ted Williams T. Williams	.526	1957	BOS	132	420	96	163	28	1	38	87	119	5	43	0	1	546	307	67	0	2	33	11	.388	.731	1.257	148	87.3	.524	223	79
6	Barry Bonds B. Bonds	.515	2001	SFG	153	476	129	156	32	2	73	137	177	9	93	13	3	664	411	107	0	2	35	5	.328	.863	1.379	200	117.7	.537	234	116.6
7	Ted Williams T. Williams	.513	1954	BOS	117	386	93	133	23	1	29	89	136	1	32	0	0	526	245	53	0	3		10	.345	.635	1.148	131	71.1	.507	207	65.5
8	Mickey Mantle M. Mantle	.512	1957	NYY	144	474	121	173	28	6	34	94	146	0	75	16	3	623	315	68	0	3	23	5	.365	.665	1.177	157	87.1	.498	217	86
9	Ted Williams T. Williams	.499	1942	BSA	150	522	141	186	34	5	36	137	145	4	51	3	2	671	338	75	0			12	.356	.648	1.147	168	96.2	.524	209	86.5
10	Ted Williams T. Williams	.499	1947	BSA	156	528	125	181	40	9	32	114	162	2	47	0	1	693	335	81	1			10	.343	.634	1.133	170	91.3	.508	207	86.2
11	Ted Williams T. Williams	.497	1946	BSA	150	514	142	176	37	8	38	123	156	2	44	0	0	672	343	83	0			12	.342	.667	1.164	166	95.8	.525	214	87.5
12	Ted Williams T. Williams	.497	1948	BSA	137	509	124	188	44	3	25	127	126	3	41	4	0	638	313	72	0			10	.369	.615	1.112	156	81	.504	184	68.8
13	Babe Ruth B. Ruth	.495	1931	NYY	145	534	149	199	31	3	46	162	128	1	51	5	4	663	374	80	0				.373	.700	1.195	181	98.6	.525	206	95.1
14	Babe Ruth B. Ruth	.493	1930	NYY	145	518	150	186	28	9	49	153	136	1	61	10	10	676	379	86	21				.359	.732	1.225	192	97	.517	204	100.6
15	Arky Vaughan A. Vaughan	.491	1935	PIT	137	499	108	192	34	10	19	99	97	7	18	4		610	303	63	7			5	.385	.607	1.098	151	75	.493	194	72.7
16	Ted Williams T. Williams	.490	1949	BSA	155	566	150	194	39	3	43	159	162	2	48	1	1	730	368	85	0			22	.343	.650	1.141	182	95.5	.511	187	82.2
17	Juan Soto J. Soto	.490	2020	WSH	47	154	39	54	14	0	13	37	41	1	28	6	2	196	107	27	0	0	12	1	.351	.695	1.185	51	26.1	.478	201	25.4
18	Babe Ruth B. Ruth	.489	1932	NYY	133	457	120	156	13	5	41	137	130	2	62	2	2	589	302	59	0				.341	.661	1.150	153	79.1	.501	192	75.3
19	Frank Thomas F. Thomas	.487	1994	CWS	113	399	106	141	34	1	38	101	109	2	61	2	3	517	291	73	0	7	12	15	.353	.729	1.217	138	72.3	.499	205	71.9
20	Norm Cash N. Cash	.487	1961	DET	159	535	119	193	22	8	41	132	124	9	85	11	5	672	354	71	2	2	19	16	.361	.662	1.148	168	88.3	.488	194	79.5
21	Ted Williams T. Williams	.479	1956	BOS	136	400	71	138	28	2	24	82	102	1	39	0	0	503	242	54	0	0	11	13	.345	.605	1.084	116	57.5	.470	175	47.8
22	Edgar Martinez E. Martinez	.479	1995	SEA	145	511	121	182	52	0	29	113	116	8	87	4	3	639	321	81	0	4	19	11	.356	.628	1.107	152	72.5	.469	182	68.8
23	Lou Gehrig L. Gehrig	.478	1936	NYY	155	579	167	205	37	7	49	152	130	7	46	3	4	719	403	93	3				.354	.696	1.174	192	97.6	.512	178	85.8
24	Jason Giambi J. Giambi	.477	2001	OAK	154	520	109	178	47	2	38	120	129	13	83	2	0	671	343	87	0	9	24	17	.342	.660	1.137	162	78.3	.465	193	78.7
25	Jason Giambi J. Giambi	.476	2000	OAK	152	510	108	170	29	1	43	137	137	9	96	2	0	664	330	73	0	8	6	9	.333	.647	1.123	163	75.5	.471	182	74.3