Like many who grew up in Ireland, Irish mythology featured in most of my bedtime stories.
From Irish myths and legends starring warriors like Fionn Mac Cumhaill to slightly terrifying stories from Irish folklore, featuring the Abhartach (the Irish vampire), there was no shortage of tales to be told.
Irish Mythology boasts such a wide range of tales and stories, many of which have stood the test of time and are still present in Irish culture today.
In the guide below, we’re going to give you an insight into where Irish mythology came from, the most popular Irish myths, and why it plays such an important part in Irish culture.
Popular Stories from Irish Mythology
Now, if you’re looking to discover what Irish mythology is all about, scroll halfway down this guide. There you’ll find what it actually is and you’ll also learn about the different cycles of mythology in Ireland.
Many tales and stories that date back thousands of years have been told time and time again right the way across Ireland, usually passed from parent or teacher to child.
In the section below, you’ll discover many of the most popular Irish myths. If you’re looking to read about fairies, vampires and other slightly mad stories, drop into our Irish folklore section.
1. Fionn Mac Cumhaill and the Salmon of Knowledge
The story of the Salmon of Knowledge is one of my favourites that involves Fionn Mac Cumhaill. It all begins when a young Fionn is sent to be an apprentice with a celebrated poet named Finnegas.
It’s during his time with Finnegas that Fionn learns of a magical fish that holds the knowledge of the world. According to the poet, the person who eats the fish will inherit all of its knowledge.
One day, while the pair were sat on the banks of the River Boyne, the poet caught a glimpse of the salmon and, without hesitating, he dived into the water and caught it.
He asked Fionn to cook it for him, but under no circumstances was he to eat it. Fionn agreed and went about cooking the Salmon. After a couple of minutes, Fionn turned the salmon and burned his thumb on the searing flesh.
Without thinking, he stuck his thumb into his mouth to ease the pain. He instantly realised his mistake.
The poet returned and he knew by the look on Fionn’s face that something was wrong. You can read the full tale in our guide to the mighty Salmon of Knowledge.
2. The Cattle Raid of Cooley
The Cattle Raid of Cooley (AKA the Tain Bo Cuailnge) is one of the best-known stories that involves the warrior Cu Chulainn. The story begins with Queen Medb and an argument with her husband over who was wealthier.
Each had their servants pile up their riches in two piles side-by-side. It became immediately evident that the one thing Medb’s husband had that she didn’t was a champion bull.
Medb knew of only one bull in Ireland that would help her pip her husband. That very day she sent a servant to meet the owner and offer him great riches in exchange for a loan of the bull.
He was about to agree when he overheard one of Medb’s servants state that they’d have stolen the bull if the man turned them down. He was infuriated and he denied Medb’s request.
Medb was enraged and a battle began. However, this was no ordinary battle, oh no – on one side, there was Medb and hundreds of men. On the other, there was a young boy named Cu Chulainn. Read the full story in our guide to the Tain.
3. The Legend of the Banshee
The story of the Banshee terrified me as a child. My dad used to say that there was one living down my Nan’s back garden, and I’d always be nervous about seeing it.
Now, depending on who you speak to, Banshees (a terrifying Irish mythological creature!) take on different forms. Some say that it’s a spirit, others describe it as a fairy, of sorts. I’ve also heard it described as a ragged old woman with wild hair.
The scream of a Banshee is believed to be an omen of death. According to legend, if a person hears the scream ring out, one of their family is set to pass away shortly.
But are Banshees real? Well, there’s definitely a very clear link behind this myth and reality, and it comes in the form of the ‘Keening Woman’. Learn the full tale in our guide to the Banshee.
4. The Children of Lir
Many years ago there lived a King called Lir who was the ruler of the Irish sea. The King was married to a woman named Eva and the couple had four kids. One day, when the kids were still little, their mother died.
Soon after, the King married Eva’s sister, Aoife. Aoife was very fond of the kids at the start, but this changed. She quickly became jealous of the time that her husband spent with his kids.
Aoife soon reached breaking point and she came up with an evil plan. She decided that she would cast a spell that would transform the kids into swans for 900 years.
300 years were to be spent on Lake Derravaragh. Another 300 years were to be spent on the Sea of Moyle. And the final 300 were to be spent on the Island of Inish Glora. Read the full legend in our guide to the Children of Lir.
5. The Puca
The Puca is a mischievous little creature that’s often misunderstood as evil. Yes, the Puca can cause trouble and strife, but its interactions with humans have never lead to injury or death.
The Puca is one of many shape-shifters in Irish mythology and it has the ability to change its appearance with ease. Known to frequent quiet corners of rural Ireland, the Puca can bring either good or bad fortune.
One of the stories about the Puca that tends to be told quite a bit is how it takes on the appearance of a horse and waits outside pubs for people that have had one drink too many.
The Puca horse offers the person a lift home and, when they climb aboard, it takes them on a wild ride home, jumping over trees and through bushes, terrifying the person. Find out more about its tricky ways in our guide to the Puca.
6. The Pursuit of Diarmuid and Grainne
The pursuit of Diarmuid and Grainne all begins when Grainne, the daughter of Cormac MacAirt, is set to marry the warrior Fionn Mac Cumhaill. It’s at their engagement party that Grainne is first introduced to Diarmuid.
It was love at first sight. Now, Grainne had a problem – she needed to tell Diarmuid how she felt, but the room was full of people. So, she decided to drug the food and drink and wait for people to konk out.
Soon after, Grainne and Diarmuid were the only two left standing and it was then that Grainne expressed her feelings. At first, Diarmuid refused. Then he agreed and the two fled.
Sometime later the drugs wore off and Fionn realised what had happened. He set off on a journey to find the pair and to kill Diarmuid. Read the full story in our guide to the pursuit of Diramuid and Grainne.
7. The Morrigan
The Morrigan was one of a number of powerful Celtic Gods and Goddesses that roamed the lands of Ireland at one point.
She was primarily associated with war, fate and death and was a known shape-shifter that often favoured transforming into a crow.
The Morrigan, like the Puca, was a gifted shape-shifter and was one of the Tuatha De Danann, who were the folk of the Goddess Danu.
The Goddess Morrigan had a number of battles with Cu Chulainn and although it wasn’t at her hand that the warrior died, she was involved in the event that led to his death. Read more about the story in our guide to the Morrigan.
8. Tír na nÓg
Tír na nÓg was the land of eternal youth that existed somewhere in the western sea. The story of Oisin and Tír na nÓg is one of the most popular tales from Irish mythology.
The story begins when Oisin was off hunting with the Fianna. Out of nowhere, a beautiful princess on a white horse appeared, stating that she wanted to take Oisin with her to Tír na nÓg.
For Oisin, it was love at first sight and he immediately agreed. The pair travelled across land and sea to reach Tír na nÓg and they spent three happy years there.
Then, Oisin felt homesick and it was agreed that he could return to Ireland once his feet never touched Irish soil. When Oisin arrived in Ireland, he realised that 3 years in Tír na nÓg was 300 years in Ireland.
He was devasted. But things got much worse. Discover what happened in our guide to Tír na nÓg.
9. The Legend of the Giant’s Causeway
One day, Fionn was visited by a messenger from Scotland. The messenger had been sent by a Scottish giant who wanted to challenge the Irish giant to a fight.
Fionn agreed and he made his way to Scotland, using great chunks of land that now form the Giants Causeway. When Fionn reached Scotland, he saw his opponent in the distance.
The giant was huge. Fionn retreated to Ireland and came up with a cunning plan to terrify the Scottish giant. Read all about it in our guide to the Giant’s Causeway legend.
10. The Abhartach (Irish Vampire)
The Abhartach is arguably the scariest of the many creatures to inhabit the worlds of Irish mythology. The story of the Abhartach all began with Patrick Weston Joyce, an Irish historian.
Joyce published a book in 1869 titled ‘The Origin and History of Irish Names of Places.’ It was in this book that the world was first introduced to the Abhartach. The Irish vampire.
The book contains a story about a place in Derry called Slaughtaverty. It was here where, many years ago, an evil dwarf that possessed magical powers lived.
The dwarf terrorised the local community until one day a local chieftain killed and buried it. It escaped the grave the following day and returned for blood. Read the full story in our guide to the Abhartach.
11. The Death of Cu Chulainn
We were told many tales about Cu Chulainn growing up in Ireland, but it wasn’t until many years later that I first heard the story of how he died.
The warrior’s death came about when the sons of the men that he killed over the years came together to seek revenge. The story goes that Cu Chulainn’s fate was sealed when he broke a taboo.
In ancient Ireland, the refusal of hospitality and the eating of dog meat were two well-known taboos. One day, while out hunting, Cu Chulainn was approached by an old hag who offered him dog meat.
If he said no, he’d break a taboo. If he said yes, he’d break a taboo. His hands were tied. He turned away the hospitality and, soon after, he entered his final battle. Learn all about it in our guide to Cu Chulainn.
12. Tuatha dé Danann
The Tuatha dé Danann were the fiercest rulers to ever roam Ireland. They were a supernatural race that arrived in Ireland when it was ruled by the Fir Bolg.
When they landed in Ireland, they immediately travelled to the west to see the Fir Bolg and to demand half of Ireland. The Fir Bolg refused and a battle commenced.
The Tuatha dé Danann came out on top and they went on to rule Ireland for many years. Read all about this mysterious race in our guide to the Tuatha dé Danann.
What Actually is Irish Mythology?
Mythology refers to a collection of myths from many years ago that tell the stories of a group of people. Everyone from the Roman’s to the Greeks had their own form of mythology.
It was within these narratives that gifted story-tellers explained how the world evolved to become what it is today. It’s believed that Irish mythology dates back thousands of years to when the Celts arrived in Ireland.
The Cycles of Irish Mythology
Irish mythology falls into 4 different cycles. Each of the cycles (Mythology Cycle, Ulster Cycle, Fenian Cycle and Cycles of the Kings) are unique and are filled with different stories.
In the section below, you’ll discover each cycle, what they’re about and you’ll also get an insight into the stories that belong to them.
The Mythological Cycle
The Mythological Cycle is the earliest cycle in Irish mythology. It revolves around a number of stories that feature ‘godlike peoples’. Many of the stories from this cycle feature the Tuatha Dé Danann.
The Mythological Cycle tells of five invasions of Ireland that were paramount in the forming of the country. This cycle offers an insight into how the island of Ireland first came to be inhabited and it details the many struggles that followed those who came here.
The Ulster Cycle
Next up is the Ulster Cycle, which many say took place around the first century. It’s during this cycle that we’re introduced to many a warrior and mighty battle.
This cycle of Irish mythology brought us the warriors of King Conchabar, the most prominent of which is the legendary Cu Chulainn.
The Fenian Cycle
The Fenian Cycle of Irish mythology primarily focuses on the great warrior Fionn Mac Cumhaill and his many exploits, like the legend of the Salmon of Knowledge.
This cycle tends to revolve around the institution of warriors, with the stories of the Fianna taking centre stage at the beginning.
The Cycles of the Kings/ Historical Cycle of Irish Myths
The final cycle of Irish mythology is the Historical cycle. This cycle blends history with mythology and its main characters are Labraid Loingsech (myth) and Brian Boru (real).
The Cycles of the Kings dates to after Saint Patrick came to Ireland and it’s said to have been influenced by Christian teachings.
FAQs about Irish legends
We’ve had a lot of questions over the years asking about everything from ‘What Irish myths are good for kids?’ to ‘What Irish legends are the creepiest?’.
In the section below, we’ve popped in the most FAQs that we’ve received. If you have a question that we haven’t tackled, ask away in the comments section below.
What is the most famous Irish myth?
You could argue that the most widely known Irish mythology stories are the ones about Cu Chulainn and Fionn Mac Cumhaill, as they tend to be told in schools.
What are the different Cycles of Irish Mythology?
The Cycles of Irish Mythology are The Mythological Cycle, The Fenian Cycle, The Ulster Cycle and the The Cycles of the Kings.
Keith O’Hara has lived in Ireland for 34 years and has spent most of the last 10 years creating what is now The Irish Road Trip guide. Over the years, the website has published thousands of meticulously researched Ireland travel guides, welcoming 30 million+ visitors along the way. In 2022, the Irish Road Trip team published the world’s largest collection of Irish Road Trip itineraries. Keith lives in Dublin with his dog Toby and finds writing in the 3rd person minus craic altogether.