The Indianapolis Colts have We Are The Colts.
Nashville SC (logo in avatar) commissioned their own song, an alt-country dirge with a sing-along part, from a local band:
(Pretend I got this to embed properly: https://youtu.be/-mCe5wR2ofQ)
Nashville’s CEO had the same role at Liverpool and was from there, so he wanted something to serve as a “You’ll Never Walk Alone” proxy. It’s played a few minutes after the end of each game after the appropriate win/draw/loss song (e.g., “Gold Don’t Rust” by the Weeks); the players come over to the main supporters section and thank the fans.
I forgot that this song was a thing in the 80s. It’s cringy now but it made sense at the time. The Raiders were the biggest rival to the Seahawks. There was also merchandise; I remember my parents with Raider Busters t-shirts.
No matter how often management tries to change it, the theme song of the Montreal Canadiens will always be “Les Canadiens Sont La” (based on an old French song called “Les Montagnards Sont La”). LES CANADIENS SONT LÀ (youtube.com)
The Blue Jays have “OK Blue Jays” which has kind of a Randy Newman-ish vibe.
There’s also Elton John’s “Philadelphia Freedom” which was written for Billie Jean King’s tennis team.
Since it was used at a high-school basketball game I was at in 1969 (while the song was still getting pop airplay), I’d have to disagree with that. The White Sox may have been the first major-league team to use it, but it had been around in sports venues for years by then.
Lord, I hate that song. Glad I’m not a Seahawks fan.
Beat me to it. It’s after my time but I head bob to it when watching games on TV.
“I Love LA” is also played after the Lakers win, but it is definitely NOT overplayed. It should be played 49 times each season (after all 41 regular season home games and then twice during each playoff series as part of their four-game sweeps of each opponent).
Most college teams have Fight Songs.
Alabama sort of adopted Deacon Blues and USC is forever playing Tusk.
I would count the Notre Dame Fight Song as the most recognized tune, but I don’t know if it’s used anywhere besides football.
Nippon Professional Baseball teams have fight songs.
Here’s a YouTube playlist with renditions of most of them.
The most current song for the most current version of the Cleveland baseball team is “We Are Cleveland” by a local band I’ve never heard of outside of Guardians games called Welshly Arms.
I was not a fan of the song when it first came out, and it’s not that good in full, but the team has been so fun since the name change that I can’t help but get pumped when I hear this stupid song.
Also they’ve been playing “Cleveland Rocks” at the end of every baseball and Cavaliers basketball game for who knows how long. As far as I know it’s the Presidents of the United States version so it could only go back to 1997.
Here’s a supposed explanation of the song and why it’s for both teams (found on a Facebook link via Google):
In 1972 Lee Ofman, a musician from Houma, Louisiana, wrote the song “Miami Dolphins Number One”. The corny song with a banjo would later become the team’s fight song. After writing the song, he made 10,000 copies and hired an agent to promote it. After hearing nothing, Ofman assumed his song would disappear forever. But after the Dolphins won Super Bowl VII, fans began singing Ofman’s song. A friend called him in Louisiana to tell him the news. Apparently nobody knew Ofman wrote the song. He even called a Miami Top 40 radio station which played his song to tell them he was the songwriter. The program director laughed and hung up on him.
Angered at the time, Ofman wrote another version of the song for the Houston Oilers and changed the lyrics. It became a huge hit in Houston during the Earl Campbell and Bum Phillips era. He made more money on the Oilers version. But his song was still popular in Miami. Miami Dolphins Number One is still played after every Dolphins score. A few year ago, hip hop artist T-Pain performed a techno-version of the song. Owner Stephen Ross wanted the new version played. But it received poor reviews from fans and even players. “That (T-Pain version) sounds terrible,” said former linebacker Channing Crowder. “The old one, it’s classic. It’s not the greatest song in the world, but I like the classic one better than that.”
That official version of “Here Come the Hawks” (and I do believe it’s the team’s official fight song) was performed, by Chicago ad guy, jingle writer, composer, and musician Dick Marx, the father of 1980s singer Richard Marx. 
Carolina Hurricanes have used “Rock You Like a Hurricane” by the Scorpions for as long as I can remember.
“TSOP (The Sound of Philadelphia)” is played at every Phillies home game.
This was in no way an official theme song. Unfortunately it was hard to get away from in 1999.
