The Bulgarian international, who has 29 international caps, was snapped up by the Cottagers in a beat-the-deadline deal as Martin Jol seeks to add more depth to his squad.
After three years in Holland, the 29-year-old right-back will provide another right-back option for the west-London outfit, where Sascha Riether has played in each of the Cottagers' 24 Premier League games this season.
Manolev told the club website: "I came here to play but I know that I have to fight for my place. I am looking forward to playing the Premier League because I believe it is the best competition in the world.
"I know Martin Jol already because when I came to Holland, we played against Ajax when he was the coach. I hope that if I play well here then I will be able to stay beyond the summer."