Dyer, 32, who made the last of his 33 England appearances in August 2007, was ravaged by injuries during the last two seasons at West Ham United.
Dyer, a free agent, has started only nine league matches in the last two seasons but QPR manager Neil Warnock played down fears he was taking a gamble on the player, telling the club's website: "When a player of Kieron's ability becomes available you'd be crazy not to to be interested.
"As far as I am concerned it is a gamble worth taking. He really impressed me in training and it looks like he has been working hard on his fitness throughout the summer."
Bothroyd, 28, who made his England debut last season playing the last 17 minutes of the 2-1 defeat to France at Wembley, has signed a three-year deal as a free agent following his exit from Cardiff City at the end of last season.
He was originally at QPR's centre of excellence from the age of nine, before embarking on a career that took him to Arsenal, Coventry City, Perugia, Blackburn Rovers on loan, Charlton Athletic, Wolverhampton Wanderers, Stoke City on loan and Cardiff.
