The 1998 All Japan Grand Touring Car Championship was the sixth season of Japan Automobile Federation GT premiere racing. It was marked as well as the sixteenth season of a JAF-sanctioned sports car racing championship dating back to the All Japan Sports Prototype Championship. The GT500 class champion was the #23 Pennzoil NISMO Nissan Skyline GT-R driven by Érik Comas and Masami Kageyama, and the GT300 class champion was the #25 Team Taisan Jr with Tsuchiya MR2 driven by Keiichi Suzuki and Shingo Tachi, who won a record five championship races, plus the post-season all-star race, giving them a total of six wins in 1998.

The season was marred by a horrific crash at the All Japan Fuji GT Race on May 3, 1998, when Ferrari Club of Japan driver Tetsuya Ota lost control of his Ferrari F355 in heavy rain and fog, and crashed into the stationary Porsche 911 of Tomohiko Sunako. Ota's car erupted into flames upon impact, and fellow racer Shinichi Yamaji rushed to extinguish the fire. Ota suffered severe burns and nerve damage that would force him to retire from full-time racing. Sunako suffered a broken leg, but would continue to race in the series later on.

1998 also saw the first GT500 class victory for Honda, at the Japan Special GT Cup at Fuji Speedway.

Team	Make	Car	Engine	No.	Drivers	Tyre	Rounds
Nismo	Nissan	Nissan Skyline GT-R	Nissan RB26DETT 2.7 L Twin Turbo I6	2	Masahiko Kageyama	B	All
					Aguri Suzuki		1, 3–7, NC
					Pedro de la Rosa		2
				23	Masami Kageyama		All
					Érik Comas		1, 3–7, NC
					Ralph Firman		2
Hasemi Motorsport	Nissan	Nissan Skyline GT-R	Nissan RB26DETT 2.7 L Twin Turbo I6	3	Masahiro Hasemi	B	All
					Tetsuya Tanaka		All
Team 5ZIGEN	Toyota	Toyota Supra	Toyota 3S-GT 2.0 L Turbo I4	5	Marc Goossens	D	All
					Yasutaka Hinoi		1–3
					Eiichi Tajima		4–7
INGING	Toyota	Toyota Supra	Toyota 3S-GT 2.0 L Turbo I4	6	Shinichi Takagi	B	All
					Pierre-Henri Raphanel		1, 3–7
					Anders Olofsson		2
Team Power Craft	Toyota	Toyota Supra	Toyota 3S-GT 2.0 L Turbo I4	8	Wayne Gardner	B	1–4, 6–7
					Minoru Tanaka		1–4, 6–7
Calsonic Team Impul	Nissan	Nissan Skyline GT-R	Nissan RB26DETT 2.7 L Twin Turbo I6	12	Takuya Kurosawa	B	All
					Kazuyoshi Hoshino		1, 3–7, NC
					Michael Krumm		2
Endless Sports	Nissan	Nissan Skyline GT-R	Nissan RB26DETT 2.7 L Twin Turbo I6	13	Mitsuhiro Kinoshita	Y	All
					Mitsuo Fujimura		All
Castrol Mugen	Honda	Honda NSX	Honda C32B 3.5 L V6	16	Ryo Michigami	B	All
					Osamu Nakako		All
Dome Racing Team	Honda	Honda NSX	Honda C32B 3.5 L V6	18	Katsutomo Kaneishi	B	All
					Katsumi Yamamoto		1–5
					Juichi Wakisaka		6–7, NC
Team Take One	Porsche	Porsche 993 GT2	Porsche M64/81 3.6 L Twin Turbo F6	30	Hideki Okada	B	All
					Yoji Yamada		All
Toyota Team TOM'S	Toyota	Toyota Supra	Toyota 3S-GT 2.0 L Turbo I4	36	Masanori Sekiya	D	All
					Norberto Fontana		All
				37	Toshio Suzuki		All
					Kelvin Burt		All
Toyota Team Cerumo	Toyota	Toyota Supra	Toyota 3S-GT 2.0 L Turbo I4	38	Hironori Takeuchi	B	All
					Hideki Noda		All
Denso Toyota Team SARD	Toyota	Toyota Supra	Toyota 3S-GT 2.0 L Turbo I4	39	Keiichi Tsuchiya	Y	All
					Tatsuya Tanigawa		All
Autobacs Racing Team Aguri	Nissan	Nissan Skyline GT-R	Nissan RB26DETT 2.7 L Twin Turbo I6	50	Takeshi Tsuchiya	B	All
					Satoshi Motoyama		1, 3–7, NC
					Hiroki Katoh		2
Team Taisan Advan	Chrysler	Chrysler Viper GTS-R	Chrysler Viper 8.0 L V10	55	Hideshi Matsuda	Y	1–2, 4, 7, NC
					Eiichi Tajima		1–2
					Fuminori Mizuno [ja]		4
					Anthony Reid		7
					Mitsuhiro Kinoshita		NC
Mobil 1 Nakajima Racing	Honda	Honda NSX	Honda C32B 3.5 L V6	64	Tom Coronel	B	All
					Koji Yamanishi		1–2, 4–7, NC
					Koji Sato [ja]		3
JLOC Corsa	Lamborghini	Lamborghini Diablo GT-1	Lamborghini L532 6.0 L V12	88	Naohiro Furuya	D	All
					Hisashi Wada		All
		Lamborghini Diablo Jota		777	Takao Wada		2, 4–5, 7
					Masami Sugiyama		2, 4–5, 7
Kenji Kawagoe	Porsche	Porsche 993 GT2	Porsche M64/81 3.6 L Twin Turbo F6	89	Kenji Kawagoe	D	2
					Toshikazu Kanamori		2
Raybrig Team Kunimitsu with Mooncraft	Honda	Honda NSX	Honda C32B 3.5 L V6	100	Kunimitsu Takahashi	B	All
					Akira Iida		All

Team	Make	Car	Engine	No.	Drivers	Tyre	Rounds
RE Amemiya Racing	Mazda	Mazda RX-7	Mazda RE20B 2.0 L 3-rotor	7	Shinichi Yamaji	D	All
					Haruhiko Matsumoto [ja]		All
Team Daikokuya	Porsche	Porsche 993 RSR	Porsche M64/80 3.8 L F6	9	Shuroku Sasaki [ja]	D	1–2
					Tsunefumi Hioki		1, 3
					Yukihiro Hane		3–5, 7
					Naohiro Kawano		4–5, 7
					Hideaki Ichimura		2
				99	Tsunefumi Hioki		5–6
					Kiichi Takahashi		5
					Akira Yoshitomi		6
Ability Motorsport	Porsche	Porsche 993 GT2	Porsche M64/82 3.6 L Turbo F6	10	Hidehiko Aso	D	All
					Akira Ishikawa [ja]		All
M Factory Racing Club	Nissan	Nissan Skyline GTS-R (HR31)	Nissan SR20DET 2.0 L Turbo I4	11	Hiromoto Ishimori	B	2, 4
					Kazuo Miura		2, 4
Xanavi Racing with Nismo Jr.	Nissan	Nissan Silvia (S14)	Nissan SR20DET 2.0 L Turbo I4	15	Masahiko Kondo	B	All
					Takayuki Aoki		All
Kageisen Racing Team	Mazda	Mazda Roadster (NA)	Mazda RE13B 1.3 L 2-rotor	17	Toshihiko Nogami [ja]	D	1–2, 4–5, 7
					Tomoyuki Hosono		1, 4
					Masaaki Nagashima		2, 5, 7
Racing Project Bandoh	Toyota	Toyota Celica	Toyota 3S-GE 2.0 L I4	19	Manabu Orido	Y	4–7
					Max Angelelli		4–6
					Katsumi Yamamoto		7
Hitotsuyama Racing	BMW	BMW M3 (E36)	BMW S14 2.2 L Turbo I4	21	Hiroki Katoh	D	1, 3–7
					Yasushi Hitotsuyama [ja]		1–2, 4, 7
					Mikio Hitotsuyama [ja]		3, 5–6
					Takayuki Kinoshita		2
Hirano Motorsport	Nissan	Nissan Skyline GTS-i (R32)	Nissan RB20DET 2.0 L Turbo I6	24	Toshiyuki Hirano	Y	2, 4
					Teruhiko Someba		2, 4
Team Taisan Jr. with Tsuchiya	Toyota	Toyota MR2	Toyota 3S-GTE 2.0 L Turbo I4	25	Keiichi Suzuki	Y	All
					Shingo Tachi		All
Team Ferrari Club of Japan	Ferrari	Ferrari F355 GT	Ferrari F129B 3.5 L V8	27	Tetsuya Ota	Y	1–2
					Anders Olofsson		1
					Steven Andskär		2
				28	Masahiro Yamazaki		2–3
					Hiroaki Suga		5
A'PEX	Toyota	Toyota MR2	Toyota 3S-GTE 2.0 L Turbo I4	44	Morio Nitta	D	All
					Shota Mizuno		1–3
					Peter Dumbreck		4–7
Cobra Racing Team	Porsche	Porsche 993 RSR	Porsche M64/80 3.8 L F6	51	Katsunori Iketani	Y	All
					Seiichi Sodeyama		1
					Masamitsu Ishihara		2–5, 7
					"OSAMU"		6
KRAFT	Toyota	Toyota Cavalier	Toyota 3S-GE 2.0 L I4	60	Kumi Sato [ja]	D	All
					Masaoki Nagashima [ja]		1
					Junko Mihara		2
					Akira Watanabe		3–7
Team Taeivon Ralliart	Mitsubishi	Mitsubishi FTO	Mitsubishi 4G63 2.0 L Turbo I4	61	Akihiko Nakaya	T	All
					Takahiko Hara		All
Team Gaikokuya	Porsche	Porsche 993 GT2	Porsche M64/81 3.6 L Turbo F6	70	Yoshimi Ishibashi	Y	All
					Patrick van Schoote		All
SigmaTec Racing Team	Porsche	Porsche 993 GT2	Porsche M64/81 3.6 L Turbo F6	71	Kaoru Hoshino	D	All
					Masaki Jyonai		All
Okura Rotary Racing	Mazda	Mazda RX-7	Mazda RE20B 2.0 L 3-rotor	72	Mark Porter	Y	3–7
					Yoshimi Katayama		3–4
					Isao Hirano		5–7
Cusco Racing	Subaru	Subaru Impreza WRX STI	Subaru EJ20 2.0 L Turbo F4	77	Katsuo Kobayashi	Y	All
					Hideyuki Tamamoto		All
NAC West	Nissan	Nissan Silvia (S13)	Nissan FJ20DET 2.0 L Turbo I4	79	Masanori Sugiyama	Y	2, 4
					Hiroyasu Aoyagi		2, 4
Team Daishin	Nissan	Nissan Silvia (S14)	Nissan SR20DET 2.0 L Turbo I4	81	Hideo Fukuyama	D	All
					Nobuyuki Oyagi [ja]		All
First Racing Team	Toyota	Toyota MR2	Toyota 3S-GTE 2.0 L Turbo I4	91	Masahiro Matsunaga	Y	1–3
					Yasuhisa Fujiwara		1–3
		Toyota Celica			Masahiro Matsunaga		4–7
					Yasuhisa Fujiwara		4–7
Alta Racing Team	Mazda	Mazda RX-7	Mazda RE20B 2.0 L 3-rotor	117	Toshihiro Fukazawa	Y	2, 4–5, 7
					Tetsuo Kozai		2, 4–5, 7
NSX Dream28 Competition	Honda	Honda NSX	Honda C32B 3.5 L V6	280	Hajime Oshiro	Y	4
					Mamoru Suzuki		4
Yellow Magic	Ferrari	Ferrari F355	Ferrari F129B 3.6 L V8	355	Hiroaki Suga	Y	4–5, 7
					Takayuki Ohi [ja]		4
					Tatsuyuki Fujiwara		5
					Seiichi Sodeyama		7
910 Racing	Porsche	Porsche 993 RSR	Porsche M64/80 3.8 L F6	910	Atsushi Yogo [ja]	D	All
					Tomohiko Sunako		1–2
					Shogo Kobayashi [ja]		3–4
					Takayuki Kinoshita		5–7
				911	Kiichi Takahashi		1–4, 7
					Shogo Kobayashi		1
					Kazushige Saito		2–3, 7
					Hirotaka Nakajima		4

Round	Race	Circuit	Date
1	Suzuka GT 300	Suzuka Circuit	March 22
2	All Japan Fuji GT Race	Fuji Speedway	May 3
3	HiLand GT Championship	Sendai Hi-Land Raceway	June 28
4	Japan Special GT-Cup	Fuji Speedway	August 9
5	Motegi GT Championship Race	Twin Ring Motegi	September 13
6	CP Mine GT Race	Mine Circuit	October 11
7	SUGO GT Championship	Sportsland SUGO	October 25
NC	Nicos Cup GT Allstar Race	TI Circuit	November 15

Round	Circuit	GT500 Winning Team	GT300 Winning Team
		GT500 Winning Drivers	GT300 Winning Drivers
1	Suzuka Circuit	#23 Pennzoil NISMO GT-R	#25 Team Taisan Jr with Tsuchiya MR-2
		Masami Kageyama Érik Comas	Keiichi Suzuki Shingo Tachi
-	Mt. Fuji	Race abandoned because of crash at start and subsequent fog.[1]
2	Sendai	#23 Pennzoil NISMO GT-R	#25 Team Taisan Jr with Tsuchiya MR-2
		Masami Kageyama Érik Comas	Keiichi Suzuki Shingo Tachi
3	Mt. Fuji	#64 Mobil 1 Nakajima Racing Honda NSX	#25 Team Taisan Jr with Tsuchiya MR-2
		Tom Coronel Koji Yamanishi	Keiichi Suzuki Shingo Tachi
4	Twin Ring Motegi	#16 Castrol Mugen Honda NSX	#77 Cusco Subaru Impreza
		Ryo Michigami Osamu Nakako	Katsuo Kobayashi Hideyuki Tamamoto
5	Mine Circuit	#100 Team Kunimitsu Honda NSX	#25 Team Taisan Jr with Tsuchiya MR-2
		Kunimitsu Takahashi Akira Iida	Keiichi Suzuki Shingo Tachi
6	Sportsland SUGO	#16 Castrol Mugen Honda NSX	#25 Team Taisan Jr with Tsuchiya MR-2
		Ryo Michigami Osamu Nakako	Keiichi Suzuki Shingo Tachi
NC	TI Circuit	#64 Mobil 1 Nakajima Racing Honda NSX	#25 Team Taisan Jr with Tsuchiya MR-2
		Tom Coronel Koji Yamanishi	Keiichi Suzuki Shingo Tachi

Rank	Drivers	Number/Team	Points	Wins
1	Keiichi Suzuki Shingo Tachi	#25 Team Taisan Jr with Tsuchiya MR-2	106	5
2	Manabu Orido	#19 Racing Project Bandoh Toyota Celica	46	0
3	Morio Nitta	#44 MOMOCORSE A'PEX MR-2	45	0
4	Hiroki Katoh	#21 Hitotsuyama Racing BMW M3	44	0
5	Akihiko Nakaya Takahiko Hara	#61 Team Taeivon Ralliart Mitsubishi FTO	37	0

• Super GT/JGTC official race archive (in Japanese)
• 1998 season results