The name Brendan is an Irish name derived from the Gaelic word "Brenann" meaning "prince" or "sea-warrior". It has its roots in the ancient Celtic culture of Ireland, dating back to the 5th century AD.

The name was popularized by St. Brendan the Navigator, an Irish monk who lived from around 484 to 577 AD. He is renowned for his legendary voyage across the Atlantic Ocean, which was recorded in the 9th century text "Navigatio Sancti Brendani Abbatis" (The Voyage of St. Brendan the Abbot).

One of the earliest recorded instances of the name can be found in the Annals of Ulster, an ancient chronicle compiled by Irish monks, which mentions a "Brendan of Cluain" in the year 558 AD.

Throughout history, several notable figures have borne the name Brendan. St. Brendan of Clonfert (c. 484-577 AD) was an Irish monastic saint who founded several monasteries and is the patron saint of mariners and navigators. Brendan Behan (1923-1964) was an Irish poet, short story writer, and playwright, known for his works like "The Quare Fellow" and "The Hostage".

Other famous individuals named Brendan include Brendan Gleeson (born 1955), an Irish actor known for his roles in films like "Braveheart" and the "Harry Potter" series; Brendan Bracken (1901-1958), a British politician and close confidant of Winston Churchill; and Brendan O'Carroll (born 1955), an Irish actor and writer, best known for creating and starring in the popular sitcom "Mrs. Brown's Boys".

The name Brendan has maintained its popularity, particularly in Ireland and among Irish communities around the world, as a nod to the country's rich cultural heritage and the legendary figure of St. Brendan the Navigator.