Divorce Requires Death

Some societies don't allow divorce. In societies that do, there are still people who just won't have it. After all, the vow was "until death do us part". Surely this must be taken as direct advice for how to handle a divorce?

This can go down two basic routes, murder or suicide, and the spouse who dies may be the one trying to leave or the one wanting to stay. The murder versions are often driven by greed, a desire to avoid splitting the family fortune. Other common reasons include:

Murder on the one who leaves: Often a form of Honor-Related Abuse, Love Makes You Evil, or both.
Suicide by the one who leaves: Driven to Suicide by seeing no other way out, maybe because of the above kind of ex or family.
Murder by the one who leaves: A preemptive strike to get away safely.
Suicide by the one who stays: Can't live with the loss... or maybe the shame.

Note that the attempted murder or suicide/"accident" may be unsuccessful. Or even fake.

As a Death Trope, Spoilers ahead may be unmarked. Beware.

Examples of Divorce Requires Death include:

Anime and Manga

In Ooku, Yunoshin has sold himself into (pampered) bondage in the female shogun's harem, expecting never to see home or girlfriend again. Once a man enters the ooku as a concubine, he can take no other (female) lovers than the shogun and can leave the service or the building only at his death. The shogun later let him go, by helping him Faking the Dead. is declared legally dead, his family gets a large "bereavement" payment, and the man formerly known as Yunoshin goes home to marry the Victorious Childhood Friend he loves and take her family name.

Comic Books

In Mad Magazine's parody of The Godfather Part II, when Kay demands a divorce from Michael, he refuses because it is against God's will. He then turns to family consigliere Tom Hagen and orders a "hit" on her. Hagen then tells Michael he is a good Roman Catholic for not divorcing her.

Film

Arnold Schwarzenegger's character in Total Recall: *gunshot* "Consider that a divorce."
Lord Love a Duck:

Stella Bernard: In our family we don't divorce our men; we bury 'em!

Partially Played for Laughs in The Whole Nine Yards, where the mobster wants to murder his wife because divorce is a sin for Catholics.
Double Jeopardy has the heroine's husband die in an accident and her getting wrongly convicted for murdering him. Turns out he was simply Faking the Dead, starting a new life with a new wife—whom he has already murdered, by the time the heroine finds out.
Divorce, Italian Style

Literature

Kate Daniels series: Kate mediates a Pack divorce dispute between werewolves, who traditionally mate for life. A young married wolf couple were separated for years, during which time both spouses fell in love with other people. The spouses now want to marry their new partners while joining a new pack, but their families are horrified at the idea of divorce. Kate is stumped until Curran suggests a Pack law saying "any shapeshifter joining the Pack has a one-time right to a new identity. If the husband didn't use it when he joined, declare him officially dead and let him rejoin under a new name. His former wife will officially be a widow."
In The Red Tent, Laban's treatment of Ruti has been just beyond awful, and Ruti is living in a society where only men can initiate divorce, so when she just can't take it anymore, she slits her wrists by a dry riverbed.
A rather complicated example from The Silmarillion: Finwe's wife Miriel dies in childbirth, but due to the way souls work in Valinor could come back. However, Finwe falls in love with Indis, and one of the stipulations for him remarrying is that Miriel is never allowed to return the life, because according to the laws of the Valar Finwe can't have two living wives at the same time. After he is later murdered this leads him to give up his chance to come back to return Miriel to life.

Live Action TV

In the Star Trek: Deep Space Nine episode Second Sight, we meet a famous scientist who have everything... except his wife's love. And she comes from a culture that doesn't permit divorce, so she's slowly killing herself instead. The episode ends with him killing himself instead, so that she will be free.
In one early episode of Law and Order SVU, a beautiful man is dead. It quickly turns out that his landlady was an alcoholic who had the hots for him and also had a pedophile boyfriend and a daughter. (The daughter is clearly adult, but probably supposed to be 16 or so, making the pedophile label inaccurate in a plot-relevant way.) It is quickly established that the man died protecting the girl from the "pedophile". This later turns out to be a lie: The girl was in love with the man, but he was about to leave the country and refused to take her with him. And she couldn't bear the thought to live without him. So her mind snapped, and she killed him.

Music

This is the plot behind Morcheeba's song "Women Lose Weight". In order to marry his Sexy Secretary and to avoid the complications that come with divorce:

Slick Rick: Anyway, long story short, hit the side of her Chrysler -- sent her clean over the divider! "You BASTARD!" she said, as the wreck went tumbling the hill -- I thought, she HAS to be dead.

She Daisey has a song called "A Night to Remember" He has an affair, she finds out and kills them both. The chorus states the the couple "promised him/her forever, 'till death due us part."

Mythology

In traditional Jewish Law (not to be confused with contemporary Israel), a woman cannot divorce her husband. Thus it occasionally arises that a man will refuse to give his wife a divorce, often in attempt to extort money out of her, and many legal devices are used in an attempt to pressure this recalcitrant husband into granting his wife a divorce. The story is said of Jewish Sage Rabbi Akiva Eiger, that such a man was brought before him once, with the hope that Rabbi Eiger would convince him to divorce his wife. Rabbi Eiger brings him into his study, and opens a volume of the Talmud to its first page. He turns to the man, looks him in the eye, and says, "The Talmud says here that a woman is freed from her husband in one of two ways. Through divorce, and through the husband's death. Which one would you prefer?" The man looks at Rabbi Eiger, laughs and says, "What, are you trying to threaten me?". He walks out of the study, walks out the front door, and collapses dead of a heart attack on the front steps.

Theater

Used in the old Vaudeville joke: "My wife and I have been married 50 years, and I've never once considered divorce. Murder, on the other hand..."

Western Animation

An episode of Family Guy has Quagmire getting married to a woman who turns out to be insane and threatens suicide every time he tries to divorce her.
- Another episode plays the trope for laughs. During a story told by a psychic of Peter's ancestor, who founded Quahog, he was married to a woman who resembled Meg, but when he fell in love with another woman, he had to divorce Meg. Cue cutaway to past-Peter shooting his wife.
Inverted in Corpse Bride. Elizabeth discovers that the requirement to marry Victor is to kill him, instead of when he wants a divorce.