Not strictly about trains, but it's prominent in the lyrics of "Casey Jones" by The Greatful Dead.

She caught the Katy - Blues Brothers or Taj Mahal*

Folsom Prison Blues - Johnny Cash

Midnight Special - Creedence Clearwater Revival or Leadbelly*

Love in Vain - Robert Johnson*

Locomotive Breath - Jethro Tull

Barricades and Brickwalls - Kacey Chambers

Train to Nowhere - Savoy Brown

Hear My Train A Comin - Jimi Hendrix*

*There have been loads of songs about trains or that mention trains in American blues history.. I'm barely scratching the surface, here. In the early days of the 20th century the blues artists used to travel around by hopping on freight trains to get from town to town, so they featured in many, many songs. There would have been even more songs written to the rhythm of a rolling carriage, too, that don't even mention trains at all.

I haven't seen mention of Ozzy's maybe biggest hit, Crazy Train

The Monkees - Last Train to Clarkesville

Ozzy Osbourne - Crazy Train

Gladys Knight & The Pips - Midnight Train to Georgia

Edit: also https://hellomusictheory.com/learn/songs-about-trains/

Bonus question: if you’re autistic, what are your opinions on trains? I’m personally ambivalent about trains, but they also feel like they’re my culture, because of how many of my fellow autistic nerds like trains.

Not autistic, but an urbanist and transportation engineer: trains are fucking awesome! Second only to bicycles in terms of efficiency of land-based transportation, and with such high capacity that induced demand actually becomes a positive effect for them (as opposed to a very negative effect when talking about automobiles).

Dethklok - Murder train a comin

Not autistic, probably, but trains are pretty cool. I've hopped trains before and that was fun, but I also don't recommend it.

Edit: just remembered, Townes Van Zandt - Desperados waiting for a train

Thomas The Tank Engine theme song

So many Johnny Cash songs:

https://www.discogs.com/release/12321351-Johnny-Cash-And-The-Tennessee-Two-Get-Rhythm-Story-Songs-Of-The-Trains-And-Rivers

Special Streamline by Bukka White.

Blue Railroad Train by Doc Watson

Choo Choo Train by the Box Tops

Downbound Train by Chuck Berry

Take the A Train by Esquivel

There are SO many songs about trains.

L & N Special by Christine Kittrell

Not sure it’s it’s been mentioned, but the corny and old school answer is Chattanooga Choo Choo

Til it was also the first gold selling record (1 million+)

Tom Waits - Train Song

Tom Waits - Downtown Train

Can't believe that no one has mentioned this one yet...

Arlo Guthrie - City of New Orleans

Driver 8 by R.E.M. is a great one. Will try to think of more 👍

EDIT:

• Solomon Burke's version of Fast Train
• Last Train to Trancentral - The KLF
• Blue Train - John Coltrane
• More of a tram than a train, but still in the same spirit I think - The Trolly Song - Judy Garland
• Actually the theme song to a Saturday-morning kids' TV show in the UK, The 8:15 from Manchester by Inspiral Carpets is a cracker. It might be about a bus though, I'm not sure.

EDIT 2

• How could I forget Dark and Long (Dark Train) by Underworld???
• Also by them - Techno Shinkansen
• Groovy Train - The Farm

Didn't see this here yet (though maybe I missed it)

Train Song - Vashti Bunyan

https://m.youtube.com/watch?v=U_cZyavt06U

Guus Meeuwis & Vagant - Per Spoor

The Doobie Brothers - Long Train Runnin

Casey Jones - The Grateful Dead

https://youtu.be/6QuQ-yVDQ54

Admittedly, it's train tangential

How about Runaway Train by Soul Asylum?

Crazy train

Train wreck

The one that goes “come on ride the train”

The one about the midnight train to Georgia

I think there’s one about working on a night train

Don’t stop believing has a train

City of New Orleans - written by Steve Goodman, cover by The Highwaymen - the City of New Orleans is a passenger line still operated by Amtrak between Chicago and New Orleans

The Gallopin' Goose - C. W. McCall - not exactly a train but certainly a part of railroad history, the "Galloping Geese" were a product of the declining demand for passenger rail service:

Originally running steam locomotives on narrow gauge railways, the perpetually struggling RGS developed the first of the "geese" as a way to keep its contract to run mail into towns in the Rocky Mountains in Colorado. There was not enough passenger or cargo income to justify continuing the expensive steam train service at then-current levels, but it was believed that a downsized railway would return to profitability.
[...]
Motors were not only less expensive to operate, but were also significantly lighter, thus reducing impact on the rails and roadbeds.
[...]
The first was built in 1931 from the body of a Buick "Master Six" four-door sedan.

The Legend of John Henry's Hammer - Johnny Cash (the Folsom Prison recording) - also not about a train specifically, but about the legendary railroad steel driver John Henry, I think it fits

Orange Blossom Special - written by Ervin T. Rose, cover by Johnny Cash - the Orange Blossom Special was a passenger train running between New York and Miami

*Bonus:

Dumb Ways to Die - produced by Metro Trains Melbourne as part of a public awareness campaign for railway safety in 2012

Electric Callboy - teckno train

Off the top of my head, the only real "train" focused song i know is Murdertrain a Comin' by Dethklok.

How's this one been missed?

I LIKE TRAINS - asdfmovie

For some reason I quickly found a few in my library:

• 魔法の本より (From the magical book) - sui: https://www.youtube.com/watch?v=QFUeTAMHdvk
• Hallo Bimmelbahn - Nighttrain: https://www.youtube.com/watch?v=EcXiMQ0J2So
• 柴又 (Shibamata): https://www.youtube.com/watch?v=FIw-HUP7XK0
• 衛星紀行 (Category: Satellite travelogues) - Sou: https://www.youtube.com/watch?v=fDL2UhbysVk
• シンカンセンスゴイカタイアイス (Shinkansen Too Hard Ice Cream) - Shannon: https://www.youtube.com/watch?v=O_VRIuKM9gw
• ラグトレイン (lagtrain) - inabakumori: https://www.youtube.com/watch?v=UnIhRpIT7nc
• TEKKNO TRAIN - Electric Callboy: https://www.youtube.com/watch?v=CFlhlZbeKgE
• Space Train - Kevin D'Angello: https://www.youtube.com/watch?v=WLD6vrt9rAQ
• 空奏列車 (Daydream Sky Train) - Orangestar: https://www.youtube.com/watch?v=xzoShzMIlIM
• Gordon Kill the Thomas - ピーナッツくん (peanut kun): https://www.youtube.com/watch?v=Se2gk5gG9yo
• A train MAD remix by Cano of Ruma - Kairiki bear: https://www.youtube.com/watch?v=DNikvbf7SGg

(I wouldn't mind getting pinged when you finished your playlist.)

Quad City DJs - C’mon N’ Ride It

No Use for a Name - Don’t Miss the Train

Tom Waits (original), Rod Stewart/Patty Smyth/Bob Seger - Downtown Train

Journey - Don’t Stop Belivin’

John Fogerty - Train of Fools

Guns ‘N Roses “Night Train” (though technically not about a locomotive but getting blitzed on rotgut)

I’d never contemplated how many songs reference trains.

Not sure how well it counts for being about trains, but the first one that leapt to mind for me was Jethro Tull - Locomotive Breath

It's at least got a lot of train allegory.

Trains by porcupine tree !!!!

Passage to Bangkok - Rush

Bob Dylan “It Takes A Lot To laugh, It Takes A Train To Cry” is about riding a mail train and is a great song :)

https://youtu.be/SN1ACh8lzHg

The Northern Boys - Sexy Train https://www.youtube.com/watch?v=4VXKhJfRQ7k

Zdob și Zdub & Advahov Brothers - Trenulețul (The Train) https://www.youtube.com/watch?v=bGNT5Uh-WKw

The Longest Johns - On the Railroad https://www.youtube.com/watch?v=TA5PvH8D4wQ&t=8

Electric Callboy - TEKKNO TRAIN https://www.youtube.com/watch?v=CFlhlZbeKgE

Last Train to Clarksville by the Monkees

I've got 16 songs about / relating to trains, but no idea how to export playlists from Poweramp:

• The Kleptones/24 Hours (Disc 1)/04 0835 Kick The Bus, Kick The Train.mp3.mp3
• 青春歌年鑑 90年代総集編 [Disc 1]/1-05 Choo Choo TRAIN.m4a
• Gorillaz/G Sides/07 Ghost Train.m4a
• Electric Light Orchestra/Strange Magic - The Best of Electric Light Orchestra/2-08 Last Train to London.m4a
• The Rolling Stone Women In Rock Collection [Disc 2]/2-02 Midnight Train To Georgia.mp3
• Back to the Future (Original Motion Picture Soundtrack)/08 Night Train (feat. The Starlighte.m4a
• The Guess Who/The Guess Who_ Anthology/1-20 Pain Train.m4a
• Mama Africa/04 Stop That Train.m4a
• Bob Marley & The Wailers/The Complete Wailers 1967-1972 Part 1 [Disc 2]/2-11 This Train (Alternate).m4a
• Tom Waits/Big Time/12 Train Song [Live].m4a
• The California Guitar Trio/Invitation/01 Train to Lamy Suite (pts 1-3).mp3
• The California Guitar Trio/Invitation/11 Train to Lamy pt 3 (reprise).mp3
• The California Guitar Trio/Invitation/05 Train to Lamy pt 4.mp3
• The California Guitar Trio/Invitation/07 Train to Lamy pt 5.mp3
• 8bit Project/SPICY INNOVATOR VS SUPERIOR MARIONETTE/04 ただ…逢いたくて - Together - Choo Choo T.m4a
• Gordon Lightfoot/Sunday Concert/11 Canadian Railroad Trilogy.mp3

And then one that isn't really about trains, but very good:

• The Clash/London Calling/19 Train In Vain.m4a

Honorable mentions (heard but don't own):

• City of New Orleans / John Denver version
• Take the A Train / Duke Ellington w. Ella Fitzgerald
• Rock Island Line / Stan Freberg version

I don't see it in the comments so hopefully not a repost. King gizzard and the lizard wizard - road train It's so good.

Just a small town girl, living in a loooonely world, She took the midnight train, going an-yyyy-where

How did nobody recommend I'm a Train by Albert Hammond??

Also: A Passage to Bankok by Rush

• Johnny Cash - Folsom Prison Blues (live from San Quentin version!)
• Kraftwerk - Trans Europe Express
• Half Man Half Biscuit - Time Flies By When You're The Driver Of A Train

Here's a great one from Slovenia: https://m.youtube.com/watch?v=RHtQ4ZF2rGQ

I really like this song.

My son is super into trains (not diagnosed yet, but we expect he gots the tism), we also have a playlist. A few I haven't seen mentioned:

Blackfoot - Train, Train

Peter Paul and Mary - Freight Train

Cat Stevens - Peace Train

Edit: forgot about this masterpiece (NSFW unless headphones)

Danville Girl - Pete Seeger - https://www.youtube.com/watch?v=8AMTd2B0bIc

I don't know if it will fit in your playlist but I love this song.

my top three train songs, in no particular order:
Movin' On - Johnny Cash
Echelon's Song - Red Army Choir This one is very train-y and the time signature accelerates like a steam engine accelerating
Midnight Special - Creedence Clearwater Revival

how about a whole album about trains/public transport?

https://emperorx.bandcamp.com/album/suggested-improvements-to-transportation-infrastructure-in-the-northeast-corridor

The Gambler by Kenny Rogers takes place on a train... https://www.youtube.com/watch?v=7hx4gdlfamo&t=15

Train Train by the Blue Hearts, if no one already mentioned it. https://www.youtube.com/watch?v=BSkLe-EOq5U&t=8

What about the song Trains by Porcupine Tree?

List of train songs - Wikipedia

For all your train song needs 🚂 🚃 🚆 🚄 🚅 🚉 🛤️

Does Journey’s “Don’t Stop Believing” count? Opens with a verse about taking trains!