Dominic Leone, Jaime Barría and Scott McGough were tied for the most home runs allowed / 9 by a relief pitcher in 2023, with 1.56.

	NAME	HR/9	HR	SEASON	TM	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	K%	BB%	WHIP	BABIP	RA	H/9
1	Dominic Leone D. Leone	1.56	14	2023	TOT	51	1	3	.250	0	4.67	54	0	0	0	54.0	49	28	28	28	2	16	3	235	4	9.00	4.67	1.93	23.0	11.9	1.43	.255	4.67	8.17
2	Jaime Barría J. Barría	1.56	14	2023	LAA	28	1	4	.200	0	6.05	40	0	0	0	55.0	63	37	48	23	1	17	6	246	3	6.55	3.76	1.74	16.3	9.3	1.56	.292	7.85	10.31
3	Scott McGough S. McGough	1.56	14	2023	ARI	62	2	7	.222	0	4.90	84	0	0	9	68.0	59	37	40	29	2	24	2	292	3	11.12	3.84	2.90	28.8	9.9	1.29	.276	5.29	7.81
4	Michael Tonkin M. Tonkin	1.44	13	2023	ATL	45	7	3	.700	0	4.27	75	0	0	1	80.0	64	38	41	23	2	11	1	325	2	8.44	2.59	3.26	23.1	7.1	1.09	.241	4.61	7.20
5	Brock Burke B. Burke	1.44	13	2023	TEX	53	5	3	.625	0	4.37	52	0	0	0	59.2	64	29	32	9	2	9	4	250	2	7.84	1.36	5.78	20.8	3.6	1.22	.293	4.83	9.65
6	Andrés Machado A. Machado	1.33	12	2023	WSH	44	4	1	.800	0	5.22	43	0	0	0	50.0	53	29	29	13	1	8	2	207	1	7.74	2.34	3.31	20.8	6.3	1.32	.297	5.22	9.54
7	Taylor Clarke T. Clarke	1.33	12	2023	KCR	56	3	6	.333	0	6.27	63	0	0	3	56.0	71	39	42	24	3	11	1	257	3	10.13	3.86	2.63	24.5	9.3	1.70	.381	6.75	11.41
8	Nick Sandlin N. Sandlin	1.33	12	2023	CLE	61	5	5	.500	0	3.75	66	0	0	0	60.0	38	25	28	24	2	7	1	239	0	9.90	3.60	2.75	27.6	10.0	1.03	.193	4.20	5.70
9	Jorge López J. López	1.33	12	2023	TOT	61	6	2	.750	0	5.95	49	0	0	3	59.0	67	39	42	22	8	15	3	266	5	7.47	3.36	2.23	18.4	8.3	1.51	.314	6.41	10.22
10	Mason Englert M. Englert	1.33	12	2023	DET	30	4	3	.571	0	5.57	40	0	0	0	53.1	64	33	38	16	2	7	0	241	2	6.75	2.70	2.50	16.6	6.6	1.50	.304	6.41	10.80
11	Ross Stripling R. Stripling	1.22	11	2023	SFG	11	0	0		0	5.90	33	0	0	0	39.2	50	26	26	9	1	5	0	176	2	7.49	2.04	3.67	18.8	5.1	1.49	.320	5.90	11.34
12	Giovanny Gallegos G. Gallegos	1.22	11	2023	STL	56	2	4	.333	0	4.42	59	0	0	10	55.0	54	27	28	12	0	16	0	229	3	9.65	1.96	4.92	25.8	5.2	1.20	.293	4.58	8.84
13	Trevor Richards T. Richards	1.22	11	2023	TOR	53	2	0	1.000	0	5.23	91	0	0	0	63.2	58	37	38	32	2	6	3	280	4	12.86	4.52	2.84	32.5	11.4	1.41	.326	5.37	8.20
14	Jakob Junis J. Junis	1.22	11	2023	SFG	36	4	3	.571	0	4.54	82	0	0	1	73.1	85	37	40	19	4	6	1	320	4	10.06	2.33	4.32	25.6	5.9	1.42	.363	4.91	10.43
15	Buck Farmer B. Farmer	1.22	11	2023	CIN	71	4	5	.444	0	4.20	70	0	0	3	75.0	58	35	36	29	4	10	0	309	1	8.40	3.48	2.41	22.7	9.4	1.16	.241	4.32	6.96
16	Kyle Finnegan K. Finnegan	1.22	11	2023	WSH	67	7	5	.583	0	3.76	63	0	0	28	69.1	66	29	33	24	1	46	1	288	0	8.18	3.12	2.63	21.9	8.3	1.30	.291	4.28	8.57
17	Rafael Montero R. Montero	1.22	11	2023	HOU	68	3	3	.500	0	5.08	79	0	0	1	67.1	74	38	40	29	3	21	0	298	0	10.56	3.88	2.72	26.5	9.7	1.53	.358	5.35	9.89
18	Kyle Nelson K. Nelson	1.22	11	2023	ARI	66	7	3	.700	0	3.98	63	0	0	0	54.1	57	24	27	13	1	8	1	230	1	10.44	2.15	4.85	27.4	5.7	1.29	.324	4.47	9.44
19	Brent Honeywell Jr. B. Honeywell Jr.	1.11	10	2023	TOT	40	2	4	.333	0	4.82	45	0	0	0	52.1	53	28	29	23	5	10	0	234	3	7.74	3.96	1.96	19.2	9.8	1.45	.285	4.99	9.11
20	José Cisnero J. Cisnero	1.11	10	2023	DET	63	3	4	.429	0	5.31	70	0	0	2	59.1	63	35	39	25	5	18	2	267	9	10.62	3.79	2.80	26.2	9.4	1.48	.338	5.92	9.56
21	Craig Kimbrel C. Kimbrel	1.11	10	2023	PHI	71	8	6	.571	0	3.26	94	0	0	23	69.0	44	25	28	28	4	45	1	278	4	12.26	3.65	3.36	33.8	10.1	1.04	.239	3.65	5.74
22	Pierce Johnson P. Johnson	1.11	10	2023	TOT	67	2	6	.250	0	4.02	90	0	0	13	62.2	63	28	34	30	0	28	1	277	4	12.93	4.31	3.00	32.5	10.8	1.48	.361	4.88	9.05
23	A.J. Puk	1.11	10	2023	MIA	58	7	5	.583	0	3.97	78	0	0	15	56.2	54	25	29	13	2	31	2	242	1	12.39	2.06	6.00	32.2	5.4	1.18	.317	4.61	8.58
24	Jimmy Lambert J. Lambert	1.11	10	2023	CWS	34	2	3	.400	0	5.40	41	0	0	1	36.2	40	22	26	19	1	10	3	167	0	10.06	4.66	2.16	24.6	11.4	1.61	.313	6.38	9.82
25	Erasmo Ramírez E. Ramírez	1.11	10	2023	TOT	36	3	3	.500	0	6.17	37	0	0	0	54.0	74	37	41	11	4	10	0	246	1	6.17	1.83	3.36	15.0	4.5	1.57	.348	6.83	12.33