He first joined the Scarlets in 2004, making his first appearance in the Celtic League match against Ulster in Ravenhill before enjoying spells with Carmarthen Quins, Newport Gwent Dragons and London Welsh.
He rejoined the Scarlets ahead of the 2011-12 season and has gone on to be a regular in the first team squad, making 60 appearances and scoring 247 points.
The Bancyfelin born player is a familiar figure to Nigel Davies, and Gloucester's Director of Rugby feels that he can be a fine addition to the squad.
"I've known Aled for a long time and he's a very talented player. He's got a fine tactical kicking game, can bring the best out of the players around him and, importantly, is a high percentage goal kicker.
"He's an experienced player who has played a lot of rugby for the Scarlets, both in the Rabodirect Pro 12 and in the Heineken Cup, who can be relied upon to deliver when called upon.
"He's also had significant experience playing in England as he was at London Welsh for three years. However, this is his first opportunity to play in the Aviva Premiership and I know that he's genuinely excited by the prospect.
"Aled's signing will give us an additional option at half back and I'm pleased with how the squad is shaping up for next season.
"And we're not done just yet. We're still working on a couple of signings and there are several more still to be announced."
Other new faces for the Cherry and Whites will include All Black John Afoa, Argentinian international second row Mariano Galarza, Welsh international hooker Richard Hibbard and Scottish international half back Greig Laidlaw.