Brennan is a popular Irish surname that is more current than Brian or Brendan and more unique than Conor and Aidan. The only issue with Brennan is that some people could believe you're speaking Brendan. Brennan crept to the bottom of the popularity chart in 1966 and has been in the Top 1000 ever since. There are many variations of names, but this one is most common. Brennan was first brought to America by immigrants from Ireland. Since then it has become popular among other ethnic groups as well. For example, Brennani is an Italian variation of Brennan and there's a famous singer who uses this name too. In fact, every year thousands of people are given this name because they share the same first and last initials as some famous person. Brennan is also a variant form of Brett, which was originally used to describe someone who practiced law illegally. Today this name is used as a boy's name or a girl's name depending on how it's spelled. Brenna is an Irish version of Brennan that has been used as a name in its own right. Like its more common cousin, this name is usually associated with children of lawyers or people in politics. Brendan is the oldest son of Ciaran and Nessa and is one of the Three Brethren (along with Brian and Eamon). He is considered a prophet by some Christians because he predicted his death before it happened.