The surname Brennan is derived from two different Gaelic names; O’Braonain and MacBranan.
It is one of the 30 most popular surnames in Ireland and is particularly common in Kilkenny, Mayo, Sligo and Roscommon. Brennon is another popular version of the name.
O’Braonains of Kilkenny
The original O’Braonain name was made up of two parts. The ‘O’ prefix meant that the person was a ‘male descendent of’. The female equivalent prefix was Ni which means ‘daughter of the descendent of’.
The female version of the name was less common because women took their husbands’ names when they got married.
The second part of the name – Braonain – comes from the word ‘Braon’ which means ‘sorrow’ or tear’ or ‘drop’.
The O’Braonains were an important family in Leinster. One particular sept, or branch, lived in Kilkenny and owned a lot of land. However, around the 17th century, they lost much of their wealth and eventually, many of the sept became renowned highwaymen.
The adventures of the most famous of these highwaymen are celebrated in the Irish folk song Brennan on the Moor, which was recorded by the Clancy Brothers and other top acts.
MacBranans of Roscommon
The MacBranans were an entirely different clan. Their name was also made up of two parts. The ‘Mac’ prefix means ‘Son of’ and ‘Branan’ comes from the word ‘bran’ which meant ‘raven’. Raven would have been a reference to the person’s dark coloured hair.
They lived in Co Roscommon and held power throughout the county for hundreds of years. Brennans in Connacht counties such as Roscommon, May and Sligo are likely to have descended from the MacBranans.
The earliest record of the name was in 1159 when Mac Branain was listed as Chief of Co Roscommon in the ‘Annals of the Four Masters’.
Both the O’Braonains and the MacBranans would have anglicised their names to ‘Brennan’ or ‘Brennon’ in the 17th century when it was difficult for people with Irish sounding names to find a job under British rule.
Famous Brennans throughout history
A number of Brennans have made their name in the worlds of music and acting. Enya is the most successful female Irish singer of all time. Her full name is Eithne Ní Bhraonáin which is anglicised to Enya Brennan.
She has sold 75 million albums worldwide and won four Grammy awards. She was also nominated for an Oscar for ‘Best Original Song’ for the song May It Be.
Enya’s sister Moya Brennan is also an important figure in Irish music. She has had success with her band, Clannad, which also featured her brothers, and as a solo artist.
Moya has sold 20 million albums worldwide and is nicknamed ‘The First Lady of Irish Music’.
Eileen Brennan
Eileen Brennan is an American actress who has had a long successful career in Hollywood. She received an Oscar nomination for her performance in Private Benjamin. She also won a Golden Globe and an Emmy for a TV adaption of the role. She also appeared in films such as The Sting, Jeepers Creepers and Scarecrow as well as TV shows like Will and Grace, Taxi and Blossom.
Other well-known Brennans include comedian Kevin Brennan, comic book writer T Casey Brennan and Australian poet Christopher Brennan.
Sporting Brennans
Mitch Brennan was an Australian rugby league player. He was part of St George’s 1979 Premiership winning team. Another Australian rugby league player was Les Brennan. Les played in the 1950s and is third in the all-time records for number of tries in one season.
Colt Brennan is an American Footballer who plays in the AFL. He plays as a quarterback and holds the record for the most touchdown passes in a season.
Joseph Brennan was a professional basketball player in the 1920s and 30s. He won three ABL Championships throughout his career. Jim Brennan was a member of the Canadian soccer team that won the CONCACAF Gold Cup in 2000.
Video histories of popular Irish names
Irish names and their meanings
