The 25-year-old arrives from second-tier Watford and has put pen to paper on a three-year deal.
“It’s a great feeling to have signed,” says Mariappa, who has a Fijian father and was eligible to represent the island nation but chose instead to declare his allegiance to Jamaica.
“The Premier League is the best in the world, I’m delighted to have the opportunity to come here and try to work my way into the team.”
The move is the first of Mariappa’s career as he had been a one-club man at Watford, coming through the ranks to play almost 250 games for the Hornets.
From 2009 to 2011, he played over 100 consecutive matches – one of the longest runs in the club’s history – and was vice-captain last season.
That experience would clearly have been a major boost to the Fiji national side and he was named in an extended training squad for the 2011 Pacific Games but did not take up the offer.
The chances of him playing for the country of his father’s birth therefore remained up in the air and he was not included in coach Juan Carlos Buzzetti’s squad for the recent OFC Nations Cup.
Fears that he had turned his back on Fiji were then confirmed when he accepted a call-up from Jamaica – who he qualifies for through his mother – for a friendly against Guyana in May.
Reading manager Brian McDermot is delighted to have secured Mariappa’s services as the club makes its return to the top level after a four-year hiatus.
“He’s been a very important player for Watford over a number of years,” McDermott says.
“Every single person I have spoken to has nothing but good things to say about him, both as a player and a person.”
Mariappa will be joined in representing Oceania in next season’s Premier League by New Zealand pair Winston Reid, whose West Ham United side also won promotion, and Ryan Nelsen, who recently moved from Tottenham Hotspur to Queens Park Rangers.
The campaign will be Mariappa’s second taste of top-flight football as he took part in Watford’s ill-fated 2006-07 season that ended in relegation.