MLS Most Foul-Mouthed Fans Ranked: Sporting KC Tops List, CF Montréal Most Negative

As the 2026 Major League Soccer (MLS) season heads into its final stretch, a new study has revealed which fanbases are the loudest, rudest, and most miserable online.

Action Network analyzed 533,066 comments from the subreddits of all 30 MLS clubs over the last 12 months, tracking both profanity and emotional tone.

The analysis revealed that Sporting Kansas City was the most foul-mouthed MLS fandom, with 14.28% of its comments containing swear words, while CF Montréal came out as the most negative fandom, with 56.56% of its comments carrying a negative tone.

“On the opposite end, Nashville SC was found to be the most positive fandom, with 28.07% of its comments carrying a positive tone, and CF Montréal turned out to be the most polite fandom, with only 5.23% of its comments containing swear words,” a spokesperson for the Action Network noted.

In total, 60,812 comments containing swear words were identified across the 30 clubs.

Here is the full breakdown:

The Most Foul-Mouthed MLS Fandoms

For this category, researchers tracked how many fan comments in the last 12 months included swear words.

The results show some fanbases are far more likely to let profanity fly when discussing results, referees and rivals.

Sporting Kansas City came out on top, with Orlando and Real Salt Lake not far behind, proving that frustration in the Midwest and Mountain West often comes with explicit language.

Top 5:

1. Sporting Kansas City – 14.28% of comments included swear words
2. Real Salt Lake – 13.77%
3. Orlando City SC – 13.44%
4. San Diego FC – 12.96%
5. FC Cincinnati – 12.57%

5 Most Negative MLS Fandoms

Beyond swearing, every comment was also run through a sentiment analysis tool that classified it as positive, negative or neutral. This revealed which fanbases spend the most time complaining, criticizing their club, and venting.

Interestingly, expansion side San Diego FC and Inter Miami CF, home to Lionel Messi, both ranked in the top three for negativity, showing big expectations come with big frustration.

Top 5:

1. CF Montréal – 56.56% of comments carried a negative tone
2. San Diego FC – 55.40%
3. Inter Miami CF – 54.97%
4. Sporting Kansas City – 54.13%
5. FC Cincinnati – 52.66%

The Most Positive MLS Fandoms

On the brighter side, the same sentiment analysis uncovered the fanbases that stay optimistic, even when results are tough.

Nashville SC led the league in positivity, with D.C. United and Portland Timbers fans also showing remarkable faith.

Top 5:

1. Nashville SC – 28.07% of comments carried a positive tone
2. D.C. United – 25.27%
3. Portland Timbers – 24.37%
4. Colorado Rapids – 23.60%
5. Chicago Fire FC – 23.50%

5 Most Polite MLS Fandoms

This is where the study delivered its biggest twist. The same team that was ranked as the most negative turned out to be the most polite.

CF Montréal fans complain the most, but they do it without cursing — a finding that underlines the cultural difference in how fan frustration is expressed.

Houston and Chicago followed as the next most well-mannered fanbases.

Top 5:

1. CF Montréal – 5.23% of comments included swear words*
2. Houston Dynamo FC – 8.81%
3. Chicago Fire FC – 9.54%
4. Vancouver Whitecaps FC – 9.54%
5. FC Dallas – 9.67%