Rob McElhenney is tired of having so many syllables in his last name. 

The It’s Always Sunny in Philadelphia star, 49, filed legal documents in Los Angeles to officially change his name, TMZ reported.

Rob Mac is what he’s going with, eliminating most of the name that has been difficult and annoying for the co-owner (with Ryan Reynolds) of Wrexham’s football club.

His More Better Productions has been investing in soccer teams in South America and he finds South Americans can’t wrap their tongues around his multi-syllabic surname. 

He’s been going by Rob Mac in his business endeavors for awhile.

‘As our business and our storytelling is expanding into other regions of the world and other languages in which my name is even harder to pronounce, I’m just going by Rob Mac,’ he told Variety last month.

Rob McElhenney is tired of having so many syllables in his last name. Seen here March 1. 2024

Rob was worried he might ruffle the feathers of his ancestors with the name change.

However, he soon learned that he wasn’t going to be the first McElhenney to change their moniker.

Some relatives had already made their own changes to their last name over the years. 

And those that hadn’t changed their name were excited to do so when they learned that he was. 

His wife, High Potential and Hacks star Kaitlin Olson and their two teenage boys are still getting used to the Rob Mac idea. 

‘The kids are really not happy about it, because they have that last name,’ Olson said.  ‘And so do I, legally!’

Rob and Kaitlyn met on the set of It’s Always Sunny in 2005 and began secretly dating during the FX comedy’s second season.

They married in Malibu in September 2008 and welcomed their sons in 2010 and 2012, respectively. 

The It’s Always Sunny in Philadelphia star, 49, filed legal documents in Los Angeles to officially change his name, TMZ reported. Seen here with his wife Kaitlyn Olson on April 30, 2025

Rob Mac is what he’s going with, eliminating most of the name that has been difficult and annoying for the co-owner (with Ryan Reynolds ) of Wrexham’s football club. Seen here November 17, 2022

His More Better Productions has been investing in soccer teams in South America and he finds the native people can’t wrap their tongues around his multi-syllabic surname. Seen here July 18, 2024

He’s been going by Rob Mac in his business endeavors for awhile. Seen here April 26, 2025

But they almost didn’t meet as Rob wasn’t thrilled to be casting Kaitlyn in Its Always Sunny.

Sunny came out of a low-budget project that Rob Mac, Charlie Day and Glenn Howerton dreamed up. 

At her audition, Olson read with Day, while her future husband directed. At one point, he told her to improvise.

‘I let go of the already funny stuff and concentrated on leveling up the rest of the material,’ Olson recalled to Variety. 

‘After, I called my manager and said, “The audition was great. I want this job. But I’m so pissed that I left out the funniest line that was already in there, because I was so focused on just making everything bounce better,”‘ she said.

As it turns out, McElhenney wrote that funny line. 

‘So she leaves the room, we’re no doubt 100% thinking she was awesome,’ McElhenney remembered.

‘But I don’t know if her instincts were 100% right, because she left out the funniest line,’ he said.

‘As our business and our storytelling is expanding into other regions of the world and other languages in which my name is even harder to pronounce, I’m just going by Rob Mac,’ he told Variety last month. Seen here April 30, 2025

‘Now, is it a coincidence that I happened to write that line? I was 26 years old, and probably very precious with what I was writing,’ Rob explained.

Fortunately, Rob’s partners talked him out of discarding Kaitlin for the role of Sweet Dee.

When he called to offer her the project, she turned it down because she discovered the funny lines she was reading weren’t for her character.

‘When they offered me the part, I asked for four scripts,’ she said. ‘And I was shocked, because they didn’t have anything funny for Sweet Dee.’

Sweet Dee was written as a nag, whereas the guys all got the jokes to deliver. 

McElhenney explained that with their shoestring budget, they hadn’t been able to write new scripts to reflect where they wanted to go with Dee.

He promised his future wife her character would be funny and Olson gave in and joined the cast.