SPOILER a character takes their own life in order to save the world in the last episode

Nobody commits suicide in the movie, but since IT (2017) is based on the novel of the same name, IT: Chapter Two (2019) will likely feature a scene where Stan kills himself.

No, though a character shows signs of depression and what could be read as suicide ideation (i.e. by trying to sacrifice themselves needlessly)

It's not technically suicide, but there is a discussion in Harry Potter and the Philosopher's Stone (2001) about how two parents willingly sacrificed themselves in the past to be murdered in order to save their son. The mother's death is shown on-screen in a flashback.

No-one dies by suicide, but the main character does at one point imitate his own suicide.

i mean... people have to kill a double of themself, but i don't think that counts as suicide.

In order for Steven to be born his mother had to give up her body. She knew she had to give up her body and did it anyway.

no, but someone contemplates it in pretty realistic detail, and as someone who suffers from suicidal ideation, it did trigger me to the point where i had to take sedative medication to calm down and not hurt myself.

It was revealed that the character of Mara, the previous She-Ra, had died due to crashing a spaceship into the desert, implying it killed her

A character sacrifices themselves while fighting.

A character stands on a bridge holding his previous partner’s engagement ring. Although not directly stated, it is implied he is considering jumping.

No, but theres a scene in the first episode where the character Katsuki Bakugou tells the main character Izuku Midoriya to kill himself

*SPOILER* A major character self-sacrifices, but it is not suicide.

No, but one character faked his own death

Suicide is mentioned.

No, although some characters sacrifice themselves (or are willing to sacrifice themselves) for others.

Near the start of episode 1, there’s a brief flash of Vincent Van Gogh killing himself by shooting himself in the chest.

Not directly? The father is wounded by a goat, then deliberately drops his ax and allows the goat to attack him again, which leads to his death.

Season 2 episode 6, Janet malfunctions and asks Michael to kill her. She doesn't kill herself but does use suicidal language. Season 4 episode 5, Derek reboots himself and uses suicidal language