It’s called the “F” train for a reason.

The Brooklyn-Queens line is among the filthiest in the subway system, tallying over 120 dirty-car complaints so far this year — including dozens for fecal matter, according to MTA documents obtained by The Post.

With complaints of gross subway cars surging citywide this year, the reports show the F is among the most offensive offenders.

Through the end of August, there have been 124 dirty-car complaints on the line — already 16 more than the 108 tallied in all of 2018, and well up from the 67 in 2015, sources said.

The litany of stomach-churning issues funking up the line include more than 30 reports of human waste and over 25 cases of vomit.

“Customer spread feces in car,” reads one March report.

“The usual homeless male in a wheelchair defecated in three cars,” reads another report from the month, one of several that make reference to a loose-boweled straphanger in a wheelchair.

It wasn’t immediately clear whether those reports referred to the same person, but they were among several that speak to the subway system’s growing homeless crisis.

“Sick male homeless person covered in bugs,” was the complaint in one April report.

“The customer is vandalizing the car, throwing food and debris all over the seats, walls and the floor,” reads another from January.

Another apparently homeless rider triggered a complaint in June because he was “bleeding profusely from the lip,” one of at least three trains reportedly marred by blood.

Meanwhile, two cars were flagged for unspecified “infectious waste,” another two for an unidentified “sticky substance” on the floor, and one simply with a “bad odor.”

There have been 1,623 complaints about soiled subway cars across the whole system through the end of August this year — a figure that is on pace to blow past 2018’s year-end tally of 2,058, and already more than the 1,504 reports logged in 2017.

The MTA has insisted that the climbing citywide complaints are not indicative of worsening conditions, but rather of more vigilant reporting.