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

	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	John McGraw J. McGraw	.547	1899	BAL	117	399	140	156	13	3	1	33	124	14	21	73		539	178	17	2				.391	.446	.994	140	65.2	.494	178	61.2
5	Babe Ruth B. Ruth	.545	1923	NYY	152	522	151	205	45	13	41	130	170	4	93	17	21	699	399	99	3				.393	.764	1.309	211	124.7	.571	230	120.4
6	Babe Ruth B. Ruth	.532	1920	NYY	142	458	158	172	36	9	54	135	150	3	80	14	14	616	388	99	5				.376	.847	1.379	191	120.9	.597	237	110.5
7	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
8	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
9	Billy Hamilton B. Hamilton	.521	1894	PHI	132	558	198	225	25	15	4	90	128	9	19	100		702	292	44	7				.403	.523	1.044	209	81.9	.495	157	76.2
10	Aaron Judge A. Judge	.521	2025	NYY	32	121	30	52	8	2	10	32	21	2	29	3	2	144	94	20	0	0	4	3	.430	.777	1.298	43	26.2	.544	266	26.7
11	Babe Ruth B. Ruth	.516	1926	NYY	152	495	139	184	30	5	47	153	144	3	76	11	9	652	365	82	10				.372	.737	1.253	184	105.6	.551	216	100.6
12	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
13	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
14	Babe Ruth B. Ruth	.513	1924	NYY	153	529	143	200	39	7	46	124	142	4	81	9	13	681	391	92	6				.378	.739	1.252	193	109.2	.549	210	102
15	Babe Ruth B. Ruth	.512	1921	NYY	152	540	177	204	44	16	59	168	145	4	81	17	13	693	457	119	4				.378	.846	1.359	214	127.8	.575	224	118.7
16	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
17	Rogers Hornsby R. Hornsby	.507	1924	SLN	143	536	121	227	43	14	25	94	89	2	32	5	12	640	373	82	13				.424	.696	1.203	175	96.7	.537	221	95.9
18	John McGraw J. McGraw	.505	1900	STL	99	334	84	115	10	4	2	33	85	23	9	29		447	139	16	5				.344	.416	.921	103	42.5	.458	160	38.5
19	Joe Kelley J. Kelley	.502	1894	BAL	129	507	165	199	48	20	6	111	107	5	36	46		638	305	74	19				.393	.602	1.104	194	78.6	.502	159	71.1
20	Hugh Duffy H. Duffy	.502	1894	BSN	125	539	160	237	51	16	18	145	66	1	15	48		616	374	85	10				.440	.694	1.196	203	91.3	.526	169	80.7
21	Ed Delahanty E. Delahanty	.500	1895	PHI	116	480	149	194	49	10	11	106	86	6	31	46		578	296	70	6				.404	.617	1.117	174	78.7	.510	177	76.8
22	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
23	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
24	Rogers Hornsby R. Hornsby	.498	1928	BSN	140	486	99	188	42	7	21	94	107	1	41	5		619	307	70	25				.387	.632	1.130	156	80.2	.506	196	78.1
25	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