Singles
2018 Knoxville Challenger
Final
Champion	Reilly Opelka
Runner-up	Bjorn Fratangelo
Score	7–5, 4–6, 7–6(7–2)
Events
Singles Doubles
← 2017 · Knoxville Challenger · 2019 →

Filip Peliwo was the defending champion but chose not to defend his title.

Reilly Opelka won the title after defeating Bjorn Fratangelo 7–5, 4–6, 7–6^(7–2) in the final.

	Semifinals							Final
		Nikola Milojević	3	4
	8	Reilly Opelka	6	6
								8	Reilly Opelka	7	4	77
									Bjorn Fratangelo	5	6	62
		Christopher Eubanks	64	4
		Bjorn Fratangelo	77	6

	First round							Second round							Quarterfinals							Semifinals
	1/WC	T Sandgren	6	6
		H Laaksonen	3	0				1/WC	T Sandgren	4	4
		R Quiroz	64	4					B Rola	6	6
		B Rola	77	6												B Rola	4	2
		N Serdarušić	2	4												N Milojević	6	6
		N Milojević	6	6					N Milojević	6	6
	WC	Timo Stodder	1	3				6	J Jung	0	4
	6	J Jung	6	6																			N Milojević	3	4
	4	M Mmoh	6	6																		8	R Opelka	6	6
	Q	Evan Song	2	3				4	M Mmoh	6	6
	Q	M Ymer	6	6				Q	M Ymer	3	2
		K Majchrzak	4	4											4	M Mmoh
	Q	Mi Redlicki	77	6											8	R Opelka	w/o
		M Arévalo	65	4				Q	Mi Redlicki	610	66
	Q	E Gómez	2	3				8	R Opelka	712	78
	8	R Opelka	6	6

	First round							Second round							Quarterfinals							Semifinals
	7	P Polansky	6	6
	Alt	C Harrison	2	2				7	P Polansky	3	4
		C Eubanks	7	63	6				C Eubanks	6	6
	WC	J. J. Wolf	5	77	4											C Eubanks	4
	WC	Preston Touliatos	3	2												E Karlovskiy	1r
		E Karlovskiy	6	6					E Karlovskiy	5	6	6
		JC Aragone	2	67				3	B Klahn	7	4	4
	3	B Klahn	6	79																			C Eubanks	64	4
	5	T Smyczek	3	6	6																		B Fratangelo	77	6
		J-P Smith	6	3	2			5	T Smyczek	6	77
		D Köpfer	6	2	6				D Köpfer	4	64
	Alt	M Krueger	1	6	2										5	T Smyczek	2	1
	SE	T Paul	4	4												B Fratangelo	6	6
		B Fratangelo	6	6					B Fratangelo	77	64	6
		T Kamke	6	3	6				T Kamke	64	77	4
	2	M Granollers	4	6	4

• Main Draw
• Qualifying Draw