List of railway lines in Japan (J to P)

J

 * Jikkoku Cable Line (Izuhakone Railway)
 * Jimbō Line (Group name. Composed of Kōbe Line and Takarazuka Line. Hankyu Corporation)
 * Jōban Line (East Japan Railway Company)
 * Jōetsu Line (East Japan Railway Company)
 * Jōetsu Shinkansen (East Japan Railway Company)
 * Jōhana Line (West Japan Railway Company)
 * Jōhoku Line (Central Japan Railway Company (tracks and services), Tokai Transport Service Company (services))
 * Jōhoku Line (Iyo Railway)
 * Jōmō Line (Jōmō Electric Railway)
 * Jōnan Line (Iyo Railway)
 * Jōshin Line (Jōshin Dentetsu)
 * Jōsō Line (Kantō Railway)
 * JR Kōbe Line (Nickname. West Japan Railway Company)
 * JR Kyōto Line (Nickname. West Japan Railway Company)
 * JR Takarazuka Line (Nickname. West Japan Railway Company)
 * JR Tōzai Line (West Japan Railway Company)
 * JR Yumesaki Line (Nickname. West Japan Railway Company)
 * Jukkokutōge Cable Car (Common name Izuhakone Railway)

K

 * Kabe Line (West Japan Railway Company)
 * Kada Line (Nankai Electric Railway)
 * Kagoshima Main Line (Kyushu Railway Company)
 * Kaigan Line (Kobe Municipal Transportation Bureau)
 * Kaikyō Line (Hokkaido Railway Company)
 * Kaizuka Line (Nishi-Nippon Railroad)
 * Kakamigahara Line (Nagoya Railroad)
 * Kakogawa Line (West Japan Railway Company)
 * Kamaishi Line (East Japan Railway Company)
 * Kameido Line (Tobu Railway)
 * Kamidaki Line (Toyama Chiho Railway)
 * Kamiiida Line (Common name. Transportation Bureau City of Nagoya)
 * Kamikōchi Line (Alpico Kōtsū)
 * Kamikumamoto Line (Kumamoto City Transportation Bureau)
 * Kanagawa Eastern Line (Sagami Railway, Tokyo Kyuko Electric Railway)
 * Kanamachi Line (Keisei Electric Railway)
 * Kanazawa Seaside Line (Yokohama New Transit)
 * Kanden Tunnel Trolleybus (Common name. Kansai Electric Power Company)
 * Kansai Airport Line (Translation. West Japan Railway Company)
 * Kansai Kūkō Line (West Japan Railway Company)
 * Kansai Main Line (Central Japan Railway Company, West Japan Railway Company)
 * Karasuma Line (Kyoto Municipal Transportation Bureau)
 * Karasuyama Line (East Japan Railway Company)
 * Karatsu Line (Kyushu Railway Company)
 * Kasamatsu Cable (Common name. Tango Kairiku Kotsu)
 * Kashihara Line (Kintetsu Railway)
 * Kashii Line (Kyushu Railway Company)
 * Kashima Line (East Japan Railway Company)
 * Kashima Railway Line (Kashima Railway) Closed
 * Kashima Rinkō Line (Kashima Rinkai Railway)
 * Katamachi Line (West Japan Railway Company)
 * Katano Line (Keihan Electric Railway)
 * Katsuyama Eiheiji Line (Echizen Railway)
 * Kawagoe Line (East Japan Railway Company)
 * Kawaguchiko Line (Fuji Kyuko)
 * Kawasaki Longitudinal Rapid Railway (Kawasaki City Transportation Bureau) Planned
 * Kawasaki Municipal Subway (Common name. Kawasaki City Transportation Bureau) Planned
 * Keihan Main Line (Keihan Electric Railway)
 * Keihanna Line (Kintetsu Railway)
 * Keihin–Tōhoku Line (Common name. East Japan Railway Company)
 * Keikyū Main Line (Common name. Keihin Electric Express Railway)
 * Keikyū Zushi Line (Common name. Keihin Electric Express Railway)
 * Keiō Line (Keio Electric Railway)
 * Keiō New Line (Common name. Keio Electric Railway)
 * Keisei Main Line (Common name. Keisei Electric Railway)
 * Keishin Line (Keihan Electric Railway)
 * Keiyō Line (East Japan Railway Company)
 * Kengun Line (Kumamoto City Transportation Bureau)
 * Kesennuma Line (East Japan Railway Company)
 * Kibi Line (West Japan Railway Company)
 * Kikuchi Line (Kumamoto Electric Railway)
 * Kinokuni Line (Nickname. West Japan Railway Company)
 * Kintetsu Link Line (Sangi Railway)
 * Kinugawa Line (Tobu Railway)
 * Kiryū Line (Tobu Railway)
 * Kisei Main Line (Central Japan Railway Company, West Japan Railway Company)
 * Kishigawa Line (Wakayama Electric Railway)
 * Kishin Line (West Japan Railway Company)
 * Kishū Railway Line (Kishu Railway)
 * Kisuki Line (West Japan Railway Company)
 * Kita-Alps Line (Nickname. East Japan Railway Company, West Japan Railway Company)
 * Kita-Ayase Branch Line (Common name. Tokyo Metro)
 * Kita-Matsue Line (Ichibata Electric Railway)
 * Kitame Line (Common name. Shimabara Railway)
 * Kitakami Line (East Japan Railway Company)
 * Kitano Line (Keifuku Electric Railroad)
 * Kitaōji Line (Common name. Freight. Japan Freight Railway Company)
 * Kita-Riasu Line (Sanriku Railway)
 * Kitto Line (Kyushu Railway Company)
 * JR Kōbe Line (Nickname. West Japan Railway Company)
 * Kōbe Main Line (Hankyu Corporation)
 * Kodomonokuni Line (Yokohama Minatomirai Railway Company (services), Tokyo Kyuko Electric Railway (tracks))
 * Kōen-Toshi Line (Kobe Electric Railway)
 * Koizumi Line (Tobu Railway)
 * Kokubunji Line (Seibu Railway)
 * Kokura Line (Kitakyushu Urban Monorail)
 * Kokusai Bunka Kōen Toshi Line (Osaka Rapid Railway)
 * Komaki Line (Nagoya Railroad)
 * Kominato Railway Line (Kominato Railway)
 * Kōnan Line (Kōnan Railway Company)
 * Kosaka Line (Freight. Kosaka Smelting & Refining)
 * Kosaka Railway Kosaka Line (Freight. Common name. Kosaka Smelting & Refining)
 * Kosei Line (West Japan Railway Company)
 * Kōtō Line (Freight. Mizushima Rinkai Railway)
 * Kotohira Line (Takamatsu-Kotohira Electric Railroad)
 * Kōtoku Line (Shikoku Railway Company)
 * Koumi Line (East Japan Railway Company)
 * Kōwa Line (Nagoya Railroad)
 * Kōya Line (Nankai Electric Railway)
 * Kōyō Line (Hankyu Corporation)
 * Kūkō Line (Fukuoka City Transportation Bureau)
 * Kūkō Line (Keihin Electric Express Railway)
 * Kūkō Line (Nickname. Kyushu Railway Company)
 * Kūkō Line (Nagoya Railroad)
 * Kūkō Line (Nankai Electric Railway)
 * Kurama Line (Eizan Electric Railway)
 * Kuramayama Cable Car (Kurama-dera Temple)
 * Kure Line (West Japan Railway Company)
 * Kureha Line (Toyama Chiho Railway)
 * Kurihama Line (Keihin Electric Express Railway)
 * Kurihara Den'en Railway Line (Kurihara Den'en Railway) Closed
 * Kurobe Cable Car (Common name. Tateyama Kurobe Kanko)
 * Kurobe Gorge Railway Main Line (Common name. Kurobe Gorge Railway)
 * Kururi Line (East Japan Railway Company)
 * Kusatsu Line (West Japan Railway Company)
 * Kuzuryū Line (Nickname. West Japan Railway Company)
 * Kyoto Line (Kintetsu Railway)
 * JR Kyōto Line (Nickname. West Japan Railway Company)
 * Kyōto Main Line (Hankyu Corporation)
 * Kyūdai Main Line (Kyushu Railway Company)
 * Kyushu Shinkansen (Kyushu Railway Company)

L
Lines just with numbers, such as "Line 1", are listed separately.
 * Linimo (Nickname. Aichi Rapid Transit)

M

 * Main Line (Hakodate City Transportation Bureau)
 * Main Line (Hanshin Electric Railway)
 * Main Line (Hiroshima Electric Railway)
 * Main Line (Keihin Electric Express Railway)
 * Main Line (Keisei Electric Railway)
 * Main Line (Kurobe Gorge Railway)
 * Main Line (Nagasaki Electric Tramway)
 * Main Line (Ohmi Railway)
 * Main Line (Sagami Railway)
 * Main Line (Sanyo Electric Railway)
 * Main Line (Toyama Chiho Railway) (Railway)
 * Main Line (Toyama Chiho Railway) (Tramway)
 * Maizuru Line (West Japan Railway Company)
 * Man'yō Line (Nickname. Man'yo Line)
 * Marunouchi Branch Line (Tokyo Metro)
 * Marunouchi Line (Tokyo Metro)
 * Maya Cable Line (Kobe City Urban Development)
 * Meguro Line (Tokyo Kyuko Electric Railway)
 * Meijō Line (Common name. Transportation Bureau City of Nagoya)
 * Meikō Line (Common name. Transportation Bureau City of Nagoya)
 * Meishō Line (Central Japan Railway Company)
 * Metro Seven (Operator undecided) Planned
 * Midōsuji Line (Osaka Municipal Transportation Bureau)
 * Mikajiri Line (Freight. Chichibu Railway)
 * Mikawa Line (Nagoya Railroad)
 * Miki Line (Miki Rail-Bus)
 * Mikuni Awara Line (Echizen Railway)
 * Minami Line (Hiroshima Electric Railway)
 * Minami-Alpes Abt Line (Nickname. Oigawa Railway)
 * Minamime Line (Common name. Shimabara Railway)
 * Minami Osaka Line (Kintetsu Railway)
 * Minami-Riasu Line (Sanriku Railway)
 * Minato Line (Hitachinaka Kaihin Railway)
 * Minatomirai 21 Line (Yokohama Minatomirai Railway Company)
 * Minatomirai Line (Common name. Yokohama Minatomirai Railway Company)
 * Mine Line (West Japan Railway Company)
 * Minobu Line (Central Japan Railway Company)
 * Minoo Line (Hankyu Corporation)
 * Misumi Line (Kyushu Railway Company)
 * Mita Line (Tokyo Metropolitan Bureau of Transportation)
 * Mitake Tozan Cable (Common name. Mitake Tozan Railway)
 * Mito Line (East Japan Railway Company)
 * Miyafuku Line (Kyoto Tango Railway)
 * Miyajidake Line (Former name. Nishi-Nippon Railroad)
 * Miyajima Line (Hiroshima Electric Railway)
 * Miyazaki Kūkō Line (Kyushu Railway Company)
 * Miyazu Line (Kyoto Tango Railway)
 * Mizue Line (Freight. Kanagawa Rinkai Railway)
 * Mizuma Line (Mizuma Railway)
 * Mizushima Main Line (Mizushima Rinkai Railway)
 * Monkey Park Monorail Line (Nagoya Railroad)
 * Mooka Line (Mooka Railway)
 * Mori to Mizu to Roman no Tetsudō (The Railway of Forest, Water and Romance) (Nickname. East Japan Railway Company)
 * Motoyama Branch Line (Common name. West Japan Railway Company)
 * Mt. Tsukuba Cable Car Line (Tsukuba Kanko Railway)
 * Mugi Line (Shikoku Railway Company)
 * Mukogawa Line (Hanshin Electric Railway)
 * Muroran Main Line (Hokkaido Railway Company)
 * Musashino Line (East Japan Railway Company)
 * Myōken Cable (Common name. Nose Electric Railway)
 * Myōken Line (Nose Electric Railway)

N

 * Nagahori Tsurumi-Ryokuchi Line (Osaka Municipal Transportation Bureau)
 * Nagano Line (Kintetsu Railway)
 * Nagano Line (Nagano Electric Railway)
 * Nagano Shinkansen (Nickname. East Japan Railway Company)
 * Nagao Line (Takamatsu-Kotohira Electric Railroad)
 * Nagareyama Line (Ryutetsu)
 * Nagasaki Main Line (Kyushu Railway Company)
 * Nagoya Line (Kintetsu Railway)
 * Nagoya Main Line (Nagoya Railroad)
 * Nakamura Line (Tosa Kuroshio Railway)
 * Nakanoshima Line (Keihan Electric Railway) Under construction
 * Namba Line (Kintetsu Railway)
 * Namboku Line (Kobe Rapid Railway (services) )
 * Namboku Line (Sapporo City Transportation Bureau)
 * Namboku Line (Sendai City Transportation Bureau)
 * Namboku Line (Tokyo Metro)
 * Nambu Line (East Japan Railway Company)
 * Nambu Branch Line (Common name. East Japan Railway Company)
 * Nan Line (South Line) (Freight. Akita Rinkai Railway)
 * Nanakuma Line (Fukuoka City Transportation Bureau)
 * Nanao Line (Noto Railway)
 * Nanao Line (West Japan Railway Company)
 * Naniwasuji Line (Operator undecided) Planned
 * Nankai Main Line (Nankai Electric Railway)
 * Nankō Line (Freight. Nagoya Rinkai Railway)
 * Nankō Port Town Line (Osaka Municipal Transportation Bureau)
 * Nankō-Minato-Ku Link Line (New Tram Technoport Line) (Osaka Municipal Transportation Bureau)
 * Nankō-Minato-Ku Link Line (Technoport Line) (Osaka Municipal Transportation Bureau)
 * Nara Line (Kintetsu Railway)
 * Nara Line (West Japan Railway Company)
 * Narita Line (East Japan Railway Company)
 * Narita New Rapid Railway Line (Keisei Electric Railway (services), Narita Rapid Rail Access (tracks) )
 * Naruto Line (Shikoku Railway Company)
 * Negishi Line (East Japan Railway Company)
 * Nemuro Main Line (Hokkaido Railway Company)
 * New Shuttle (Nickname. Saitama New Urban Transit)
 * Nichinan Line (Kyushu Railway Company)
 * Nihonkai Jūkan Line (Group name. Composed of JR lines running on the Sea of Japan coast. East Japan Railway Company, West Japan Railway Company)
 * Nikkō Line (East Japan Railway Company)
 * Nikkō Line (Tobu Railway)
 * Nippō Main Line (Kyushu Railway Company)
 * Nippori-Toneri Liner (Tokyo Metropolitan Subway Construction Company (constructor), operated by TOEI.)
 * Nishi-Futō Line (Freight. Mizushima Rinkai Railway)
 * Nishihino Line (Common name. Kintetsu Railway)
 * Nishikajima Line (Common name. Enshu Railway)
 * Nishikigawa Seiryū Line (Nishikigawa Railway)
 * Nishi-Kyūshū Line (Matsuura Railway)
 * Nishi-Nagoyakō Line (Nagoya Seaside Rapid Railway)
 * Nishio Line (Nagoya Railroad)
 * Nishi-Ōsaka Line (Hanshin Electric Railway)
 * Nishi-Shigi Cable Line (Kintetsu Railway)
 * Nissei Line (Nose Electric Railway)
 * Noda Line (Tobu Railway)
 * North Line (Translation. Freight. Akita Rinkai Railway)

O

 * Ōarai Kashima Line (Kashima Rinkai Railway)
 * Obama Line (West Japan Railway Company)
 * Odawara Line (Odakyu Electric Railway)
 * Ōedo Line (Tokyo Metropolitan Bureau of Transportation)
 * Ōfunato Line (East Japan Railway Company)
 * Oga Line (East Japan Railway Company)
 * Oga Namahage Line (Nickname. East Japan Railway Company)
 * Ogose Line (Tōbu Railway)
 * Ōigawa Main Line (Oigawa Railway)
 * Ōimachi Line (Tokyo Kyuko Electric Railway)
 * Ōito Line (East Japan Railway Company, West Japan Railway Company)
 * Ōkawa Branch Line (Common name. East Japan Railway Company)
 * Okinawa Urban Monorail Line (Okinawa Urban Monorail)
 * Oku-no-Hosomichi Mogamigawa Line (Nickname. East Japan Railway Company)
 * Oku-no-Hosomichi Yukemuri Line (Nickname. East Japan Railway Company)
 * Ōminato Line (East Japan Railway Company)
 * Ōmiya Line (Common name. Tobu Railway)
 * Ōmori Line (Hakodate City Transportation Bureau)
 * Ōmura Line (Kyushu Railway Company)
 * Onoda Line (West Japan Railway Company)
 * Osaka Line (Kintetsu Railway)
 * Ōsaka Higashi Line (West Japan Railway Company)
 * Ōsaka Loop Line (West Japan Railway Company)
 * Ōsaka Monorail Line (Osaka Rapid Railway)
 * Oshiage Line (Keisei Electric Railway)
 * Ōta Line (Common name. Tobu Railway)
 * Ōtemachi Line (Iyo Railway)
 * Ōtō Line (Keihan Electric Railway)
 * Otokoyama Cable (Common name. Keihan Electric Railway)
 * Ōtsu Line (Group name. Composed of Keishin Line and Ishiyama Sakamoto Line. Keihan Electric Railway)
 * Ōtsuki Line (Fuji Kyuko)
 * Ōu Main Line (East Japan Railway Company)
 * Oume Line (East Japan Railway Company)
 * Ōura Branch Line (Nagasaki Electric Tramway)
 * Ōwani Line (Konan Railway)
 * Ōyama Cable Line (Oyama Kanko Electric Railway)

P

 * Peach Liner (Nickname. Tokadai New Transit) Closed
 * Phase 1 Line (Translation. Kagoshima City Transportation Bureau)
 * Phase 2 Line (Translation. Kagoshima City Transportation Bureau)
 * Port Island Line (Kobe New Transit)