Here is the part almost everyone — including many Catholics — gets wrong: the Friday fish thing never actually went away. In the United States, every Friday of the year is still a day of penance. What changed in 1966 is that, outside of Lent, Catholics may substitute a different penance for skipping meat. Most people heard “the rule was dropped” and missed the second half of the sentence.
So the fish is not really about fish. It is about Friday — the day Jesus died — and about a very old Christian instinct that the body should take part in remembering it. This page lays out where the practice comes from, what the current rules precisely are, and which popular explanations are simply myths.
The short answer
Catholics abstain from meat on Fridays as an act of penance, because Friday is the day Christ died on the Cross. The rule forbids the flesh meat of land animals — the celebratory food of the ancient world — while fish, a humbler everyday food, is permitted. Today the abstinence strictly binds on Ash Wednesday, Good Friday, and every Friday of Lent; on other Fridays, Catholics in the U.S. are still required to do penance but may substitute another sacrifice for giving up meat.
It was never about the fish — it’s about Friday
Christians have treated Friday as a day set apart since the earliest centuries, because Friday is the day of the Crucifixion. The Catechism names Fridays throughout the year, “in memory of the death of the Lord,” among the Church’s intense moments of penitential practice (CCC 1438), and the Church’s law says it plainly: “The penitential days and times in the universal Church are every Friday of the whole year and the season of Lent” (Canon 1250).
Penance here is not self-punishment for its own sake. It is a small, bodily act of solidarity with Christ crucified — a weekly echo of Good Friday, the way Sunday is a weekly echo of Easter. Giving up something real at the table, once a week, would two generations ago have been called ordinary Christianity; today it mostly survives as the question you just googled.
Why fish doesn’t count as “meat”
The traditional discipline forbids flesh meat — the meat of warm-blooded land animals and birds. In the ancient and medieval world, that was the food of feasting: the fatted calf, the roast at a celebration. Fish, by contrast, was the ordinary, humble fare of the poor and of fishermen. Abstaining from flesh meat meant setting aside the festive food precisely on the day you were remembering a death.
St. Thomas Aquinas gives the classic explanation: the Church’s fasting laws target the foods that give the most pleasure and nourishment, and land-animal flesh headed that list (Summa Theologiae II-II, q. 147, a. 8). So the line between beef and salmon is not a biological technicality — it is a line between celebration and simplicity. That is also why the rule can feel inverted at a modern seafood restaurant: a lobster dinner keeps the letter of the law while rather missing its point, which is worth remembering more than policing.
The current rules, precisely
Here is the whole discipline as it binds Catholics today (Canons 1250–1253, with the U.S. bishops’ norms):
- ◆Ash Wednesday and Good Friday — both fasting and abstinence. Fasting (one full meal, plus two smaller meals that together don’t equal a full one) binds adults from age 18 until their 59th birthday. Abstinence from meat binds everyone 14 and older.
- ◆Fridays of Lent — abstinence from meat, binding on everyone 14 and older. No substitution is allowed during Lent.
- ◆Every other Friday of the year — still a day of penance. In the United States, abstinence from meat remains the recommended default, but the bishops permit substituting another penance: a different sacrifice, a work of charity, extra prayer.
- ◆When a solemnity falls on a Friday — the obligation is lifted entirely that day (Canon 1251). This is why Catholics may eat meat on, say, the Solemnity of St. Joseph (March 19) even in Lent.
Two myths worth burying
“The Church made the rule because fish was cheap” — backwards, and not the reason. The rule is about removing flesh meat as penance; fish is simply what remains permitted. The discipline predates any economic story you could tell about it, reaching back to the early centuries of the Church.
“A medieval pope owned a fishing fleet and invented the rule to sell fish” — a genuinely circulating myth, and there is no evidence for it whatsoever. No historian has ever produced the pope, the fleet, or the deal. Friday abstinence appears in Christian practice long before the medieval fishing economy it supposedly served. It is true that centuries of fish-on-Friday shaped food markets — that is an effect of the discipline, not its cause.
What actually changed in 1966 — and what didn’t
In February 1966, Pope Paul VI issued the apostolic constitution Paenitemini, reorganizing the Church’s penitential discipline and allowing bishops’ conferences to adapt it to local circumstances. That November, the U.S. bishops issued their Pastoral Statement on Penance and Abstinence: outside of Lent, American Catholics would no longer be bound to abstain from meat specifically — but every Friday remains a day of penance, and the bishops gave “first place” to keeping the traditional abstinence freely. Their hope was that “Friday should be in each week something of what Lent is in the entire year.”
In other words: the form became flexible; the obligation to do penance on Friday never went anywhere. If Friday penance is news to you and you want the wider context of how Catholic practice fits together, the overview of Catholic beliefs and the guide to the Mass are good next doors — and if you’re further along than curiosity, here is how becoming Catholic actually works.
Related Questions
Can Catholics eat chicken broth or meat sauce on Fridays of Lent?
The law of abstinence forbids eating flesh meat itself. Broths, gravies, and sauces flavored with meat have traditionally been treated more leniently, and trace amounts do not break the law in any serious way. The spirit of the discipline suggests avoiding them when you reasonably can, but no one should scrupulously agonize over soup stock. Penance is meant to turn the heart toward Christ, not toward label-reading anxiety.
Do eggs, milk, cheese, and butter count as meat?
No. Eggs and dairy products are not flesh meat and are permitted on days of abstinence under the current discipline. Older and stricter forms of fasting in Church history sometimes excluded them, but today’s law does not.
Is it a sin if I forget and eat meat on a Friday of Lent?
Genuinely forgetting is not a sin — sin requires knowledge and deliberate choice. If you remember mid-burger, simply stop, and take up another small penance that day if you can. Deliberately disregarding the Church’s penitential discipline out of contempt is a different and more serious matter, but an honest lapse of memory is not that.
When did the rule about meat on all Fridays change?
In 1966. Pope Paul VI’s apostolic constitution Paenitemini reorganized the Church’s penitential practice, and the U.S. bishops’ Pastoral Statement on Penance and Abstinence (November 1966) ended the binding obligation to abstain from meat on Fridays outside Lent for American Catholics — while keeping every Friday as a day of penance, with abstinence from meat recommended as the first choice.
Who is required to abstain and to fast?
Abstinence from meat binds Catholics who have completed their 14th year. Fasting binds adults from 18 until the beginning of their 60th year. The sick, pregnant and nursing mothers, and those whose health or work genuinely requires otherwise are excused (Canon 1252).
Sources & Church Teaching
- Catechism of the Catholic Church 1438 (Fridays as penitential days in memory of the Lord’s death)
- Code of Canon Law, Canons 1250–1253 (penitential days, abstinence, fasting, episcopal conferences)
- Paul VI, apostolic constitution Paenitemini (1966)
- USCCB, Pastoral Statement on Penance and Abstinence (November 18, 1966)
- Thomas Aquinas, Summa Theologiae II-II, q. 147, a. 8 (why abstinence targets flesh meat)