Ipswich have signed striker Chris Wood on loan from Leicester until the end of the season.
Watford have announced the signing of Italy international Marco Motta, subject to international clearance.
Ferrara replaced Giuseppe Iachini on Samp's return to the top flight this summer, but the former Italy Under-21 coach has paid the price for a poor start to the Serie A season in which the Blucerchiati have won just five times.
Following yesterday's 3-1 defeat at Catania, Sampdoria issued a statement on their official website outlining the personnel changes.
It read: "Sampdoria can confirm they have dismissed first-team Ciro Ferrara along with all his technical staff.
"At the same time, the club has accepted the resignations of director of sport Pasquale Sensibile and technical co-ordinator Domenico Teti.
"The club would like to thank everyone for the work they have put in over recent months and wish them all the best for their future careers.
"Sampdoria can also confirm the appointments of both Delio Rossi as first-team coach and Carlo Osti as director of sport.
"They will be presented in Bogliasco at 1pm (BST) tomorrow afternoon."
A former Juventus defender and manager, Ferrara guided newly-promoted Samp to three straight victories at the start of the current season, but came under intense scrutiny when the Ligurians lost seven straight games to slip quickly down the league standings.
The 45-year-old bought himself some more time with victory in the Genoa derby, followed by a 1-0 win over Bologna, but a run of three games without a win has persuaded Samp's management to make the change.
Rossi made his name in Italy during a four-year spell as Lazio manager, guiding the Biancocelesti to a third-placed finish in 2007 and Coppa Italia glory in 2009.
An inconsistent stint in charge of Palermo was followed by a brief, dramatic tenure at Fiorentina.
The 52-year-old was sacked in May for attempting to punch Viola midfielder Adem Ljajic when he reacted sarcastically to being substituted.
Sampdoria sit 13th in the current standings and welcome Rossi's former club Lazio to the Stadio Luigi Ferraris on Saturday.