Folan, Ramage and manager's son Cian snapped up by Blues.
The most notable arrival is of out-of-contract Republic of Ireland international striker Caleb Folan, pictured, who is joined by Peter Ramage from Queens Park Rangers and Cian Hughton, the son of manager Chris.
Ramage arrives from the Premier League outfit on an emergency loan until the end of the season and Folan and Hughton, an Irish under-21 international, have been given deals until the summer.
Folan, 29, has been training with the club since the beginning of February following his return to the UK from MLS side Colorado Rapids and has impressed boss Hughton and his coaching team.
He began his professional career with hometown club Leeds United, before switching to Chesterfield in 2003.
His performances for the Spireites saw him earn a move to Wigan Athletic in January 2007, before he was on the move again later that same year to Hull City who paid a then club record fee of pounds 1 million for him.
The powerful frontman cemented his place in the club's history by scoring the winner against Fulham in their first ever top-flight game at the KC Stadium.
He later spent three months on loan with Middlesbrough before jetting across the Atlantic in March last year to join the Rapids.
He has been capped seven times by the Republic, with his last appearance coming against Italy in the 2010 World Cup Qualifiers.
Subject to the formality of international clearance being received Folan will be available for the game against Derby County at St Andrew's on Saturday.
Ramage, a 28-year-old defender who can play at rightback or centre-half, has been on loan at Crystal Palace for the first half of the season but returned to Rangers in January. Hughton Jnr, who plays at full-back or in midfield, has been training with the club for several months and has impressed for the reserves in recent fixtures.
He began his career at Tottenham's academy before going on to spend two years with Lincoln City and will primarily spend his time with Richard Beale's development squad.