Former Oldham striker Smith joins Fulham from Leeds United for an undisclosed fee on a three-year deal, with the option of a further 12 months included.
Smith scored 14 goals in 47 appearances for Leeds and the towering frontman is now reunited with former Elland Road strike partner Ross McCormack at Craven Cottage.
Wales international midfielder Huws has made his loan move from Manchester City to Wigan permanent under a four-year deal in unexpected circumstances.
Last month, the 20-year-old joined Wigan on a six-month loan on the same day he penned a new contract at the Etihad Stadium running until 2016.
City's elite development squad boss Patrick Vieira told the club's official website at the time: "Emyr is a great talent of this club which he proved on loan at Birmingham City last year.
"I'm really pleased he's both agreed to stay on at City until 2016 and that he’s taken this opportunity Wigan have offered him."
Huws has since featured in every Championship game for Wigan this season and manager Uwe Rosler is delighted to have secured his services for an undisclosed fee.
"Emyr has impressed everyone since arriving at the club and we feel that he can have a major role to play in the future of the club," he told Wigan's official website.
"Everybody can see what a very talented player Emyr is, and from the first training session with us leading through to the games he has played, he has been very good.
"At just 20 years old he is already with the full Welsh national team and the chance to sign him on a long-term contract was too good an opportunity to turn down."
Earlier on deadline day, Wigan secured the signings of Adam Forshaw, Adam Delort and William Kvist as they chase a return to the top flight.