Juan Soto has the most career walks by a player younger than 25, with 640 walks.

Interpreted as:

most walks before turning 25 years old by a player

	NAME	BB	G	AB	R	H	2B	3B	HR	RBI	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Juan Soto J. Soto	640	779	2,704	527	768	148	11	160	483	12	577	50	19	3,374	1,418	319	2	16	65	74	.284	.421	.524	.946
2	Mel Ott M. Ott	540	983	3,367	680	1,059	195	31	176	713	18	258	38		3,978	1,844	402	53				.315	.412	.548	.960
3	Mickey Mantle M. Mantle	522	808	2,944	641	907	136	43	173	575	5	580	42	18	3,491	1,648	352	9	11	12	21	.308	.412	.560	.972
4	Ted Williams T. Williams	493	586	2,104	541	749	154	33	127	515	12	196	11		2,613	1,350	314	4			45	.356	.481	.642	1.122
5	Eddie Yost E. Yost	490	708	2,598	411	684	131	27	34	233	26	274	24	4	3,157	971	192	43			54	.263	.385	.374	.759
6	Eddie Mathews E. Mathews	470	732	2,634	497	735	119	24	190	492	7	445	26	14	3,141	1,472	333	13	17	37	35	.279	.387	.559	.946
7	Jimmie Foxx J. Foxx	461	810	2,750	612	923	159	57	174	668	5	377	29		3,270	1,718	390	54				.336	.432	.625	1.057
8	Bryce Harper B. Harper	455	768	2,756	507	785	149	18	150	421	17	665	62	28	3,262	1,420	317	9	25	54	59	.285	.386	.515	.902
9	Mike Trout M. Trout	436	762	2,837	565	868	168	35	160	471	41	735	130	23	3,348	1,586	363	0	34	42	38	.306	.402	.559	.961
10	Rickey Henderson R. Henderson	434	649	2,414	473	703	102	25	35	213	15	335	427	120	2,891	960	162	15	13	20	33	.291	.401	.398	.798
11	Arky Vaughan A. Vaughan	412	723	2,695	501	906	149	61	53	430	24	126	33		3,180	1,336	263	49				.336	.429	.496	.924
12	Donie Bush D. Bush	408	613	2,156	450	543	63	21	6		13		179		2,712	666	90	135				.252	.374	.309	.683
13	Ken Griffey Jr. K. Griffey Jr.	374	845	3,180	518	972	194	19	172	543	18	477	88	41	3,606	1,720	385	5	29	100	64	.306	.379	.541	.920
14	Buddy Lewis B. Lewis	363	848	3,497	583	1,069	172	63	49	426	11	210	66		3,920	1,514	284	49			27	.306	.373	.433	.806
15	Adam Dunn A. Dunn	348	501	1,728	313	430	92	4	118	273	28	565	37	14	2,112	884	214	1	7	34	24	.249	.382	.512	.893
16	Cass Michaels C. Michaels	346	800	2,738	309	726	88	32	25	320	17	237	42		3,149	953	145	48			80	.265	.351	.348	.699
17	Harlond Clift H. Clift	346	534	1,988	413	577	115	29	65	274	18	266	22		2,368	945	209	16				.290	.400	.475	.875
18	Al Kaline A. Kaline	343	904	3,368	521	1,047	156	34	125	544	16	289	51	34	3,776	1,646	315	19	30	41	89	.311	.374	.489	.863
19	Butch Wynegar B. Wynegar	331	723	2,510	305	642	103	9	36	307	14	238	8	6	2,920	871	148	43	22	25	54	.256	.343	.347	.690
20	Miguel Cabrera M. Cabrera	329	735	2,750	457	857	185	10	141	534	25	605	17	11	3,136	1,485	336	5	27	70	89	.312	.387	.540	.927
21	Frank Thomas F. Thomas	328	420	1,482	276	471	101	7	71	290	9	278	7	6	1,840	799	179	0	21	22	46	.318	.439	.539	.978
22	Rusty Staub R. Staub	323	833	2,906	297	792	156	12	57	370	21	311	8	6	3,306	1,143	225	27	29	75	74	.273	.346	.393	.740
23	Giancarlo Stanton G. Stanton	318	634	2,288	350	619	138	8	154	399	23	742	30	10	2,640	1,235	300	0	11	50	49	.271	.364	.540	.903
24	Elbie Fletcher E. Fletcher	310	626	2,206	300	591	100	23	36	276	19	205	19		2,559	845	159	24			24	.268	.363	.383	.746
25	Andruw Jones A. Jones	307	847	3,040	496	812	156	23	156	479	30	635	109	37	3,407	1,482	335	6	24	24	56	.267	.338	.488	.825