Luka Doncic and LeBron James are tied for the most games by a player younger than 21 with 30+ points in a season, with 27 games.

most 30 point games in a season before turning 21

Interpreted as:

most 30 or more point games in a season before turning 21 years old by a player

NAME	GP	PTS	AGE	SEASON	TM	MPG	PPG	RPG	APG	SPG	BPG	TPG	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	MIN	REB	AST	STL	BLK	TOV	PF	+/-
Luka Doncic	27	959	20	2019-20	DAL	35.3	35.5	11.1	10.0	0.9	0.4	4.2	11.6	22.9	50.5	4.1	10.5	39.2	8.3	10.6	78.3	953	299	271	25	11	113	71	+206
LeBron James	27	969	20	2004-05	CLE	44.8	35.9	7.6	6.4	2.5	0.5	3.5	12.6	25.1	50.4	2.3	5.5	41.2	8.4	10.6	78.7	1,209	206	174	68	13	94	54	+36
Zion Williamson	21	711	20	2020-21	NOP	36.0	33.9	7.6	4.0	0.9	0.6	2.8	13.2	19.5	67.6	0.2	1.0	25.0	7.2	10.1	71.4	756	159	83	18	12	58	43	+19
Kevin Durant	21	718	20	2008-09	OKC	42.7	34.2	7.5	3.4	1.1	1.0	3.0	12.0	22.0	54.4	2.1	4.1	51.2	8.2	9.2	89.1	898	158	72	24	21	63	42	-46
Jalen Green	16	541	20	2022-23	HOU	36.2	33.8	3.6	3.6	0.6	0.1	2.9	11.4	21.1	54.3	4.0	8.6	46.4	6.9	8.6	81.0	579	57	57	10	2	46	27	+46
Devin Booker	14	517	20	2016-17	PHX	38.7	36.9	3.3	4.3	0.9	0.1	3.6	12.5	24.8	50.4	3.7	7.3	51.0	8.2	9.4	87.1	542	46	60	13	2	50	54	+1
Kyrie Irving	13	441	20	2012-13	CLE	36.4	33.9	3.8	5.2	2.2	0.3	3.4	12.0	22.1	54.4	2.8	5.5	50.0	7.2	7.4	96.9	474	49	68	28	4	44	28	+6
LeBron James	13	445	19	2003-04	CLE	44.5	34.2	7.2	6.5	1.7	0.7	3.9	12.8	24.6	51.9	1.8	4.1	45.3	6.8	8.1	84.8	578	93	84	22	9	51	15	+34
Victor Wembanyama	11	365	20	2023-24	SAS	33.6	33.2	12.5	4.8	1.3	4.2	4.4	11.5	21.6	53.4	3.2	7.6	41.7	6.9	8.5	80.9	370	138	53	14	46	48	25	+51
Andrew Wiggins	10	318	20	2015-16	MIN	39.0	31.8	4.7	3.0	1.3	1.2	2.7	11.3	20.3	55.7	2.0	3.8	52.6	7.2	9.3	77.4	390	47	30	13	12	27	17	+57
Carmelo Anthony	10	345	19	2003-04	DEN	40.4	34.5	5.7	2.8	1.3	0.4	3.5	12.9	22.2	58.1	1.8	3.3	54.5	6.9	8.4	82.1	404	57	28	13	4	35	38	+48
Shaquille O'Neal	10	345	20	1992-93	ORL	40.1	34.5	17.1	2.0	0.7	4.1	4.3	14.1	20.5	68.8	0.0	0.0		6.3	10.4	60.6	401	171	20	7	41	43	32
Anthony Edwards	9	339	20	2021-22	MIN	38.4	37.7	6.3	4.6	1.9	0.9	3.1	13.2	24.2	54.6	5.9	12.7	46.5	5.3	7.0	76.2	345	57	41	17	8	28	20	+76
LaMelo Ball	9	296	20	2021-22	CHA	36.5	32.9	7.6	7.8	2.4	0.3	3.4	11.6	21.8	53.1	5.9	10.7	55.2	3.9	4.8	81.4	328	68	70	22	3	31	30	+40
Trae Young	9	314	20	2018-19	ATL	38.1	34.9	4.2	10.9	0.6	0.3	3.8	12.0	22.3	53.7	4.6	9.9	46.1	6.3	7.0	90.5	343	38	98	5	3	34	23	+62
Anthony Davis	9	297	20	2013-14	NOP	41.8	33.0	12.7	2.0	1.3	3.2	2.0	12.4	20.1	61.9	0.0	0.0		8.1	9.8	83.0	376	114	18	12	29	18	21	+25
John Drew	9	323	20	1974-75	ATL	37.1	35.9	15.6	3.3				13.2	25.4	52.0				9.4	12.8	73.9	334	140	30				38
Jalen Green	8	259	19	2021-22	HOU	38.4	32.4	3.8	2.9	0.5	0.6	1.5	11.5	22.4	51.4	5.3	11.1	47.2	4.1	5.0	82.5	307	30	23	4	5	12	17	-12
Luka Doncic	8	260	19	2018-19	DAL	35.0	32.5	7.6	6.0	1.9	0.3	3.6	10.8	20.3	53.1	3.8	8.5	44.1	7.3	10.4	69.9	280	61	48	15	2	29	17	+18
Jamal Murray	7	225	20	2017-18	DEN	35.6	32.1	4.4	3.4	0.6	0.4	1.4	12.0	19.7	60.9	4.1	7.1	58.0	4.0	4.4	90.3	249	31	24	4	3	10	25	+54
Kevin Durant	7	241	19	2007-08	SEA	41.3	34.4	7.3	3.4	1.3	1.6	4.3	12.4	22.0	56.5	1.4	3.6	40.0	8.1	9.3	87.7	289	51	24	9	11	30	15	+26
Carmelo Anthony	7	231	20	2004-05	DEN	38.4	33.0	7.6	2.6	1.6	1.3	3.1	10.4	19.4	53.7	0.9	2.6	33.3	11.3	12.6	89.8	269	53	18	11	9	22	25	+71
Cliff Robinson	7	233	20	1980-81	NJN	36.0	33.3	9.4	1.9				14.7	25.1	58.5	0.0			3.9	5.1	75.0	252	66	13				25
Paolo Banchero	6	185	20	2022-23	ORL	35.7	30.8	9.2	4.2	1.0	0.8	2.7	10.3	21.0	49.2	2.2	5.0	43.3	8.0	9.2	87.3	214	55	25	6	5	16	16	+8
Devin Booker	6	197	19	2015-16	PHX	40.6	32.8	2.8	3.2	0.5	0.3	3.7	11.3	22.7	50.0	3.2	7.3	43.2	7.0	8.2	85.7	244	17	19	3	2	22	20	-71