The pair, who both won promotion to the Premier League last season, have turned loan deals into permanent moves, with both players putting pen-to-paper on three-and-a-half-year contracts until the summer of 2017.
Cairney joined Rovers until the turn of the year from Hull City back in August, netting twice in 24 appearances in a successful first half of the season.
The 22-year-old has been an instant hit with the Ewood faithful with his classy displays in midfield, none more so than last time out against Leeds United when he set up both goals in Rovers' 2-1 away win.
Cairney said: “I’m very pleased to sign permanently – that was a goal of mine when I came on loan in August.
“First and foremost, I wanted to try and get games under my belt. I knew it was a big club, with a lot of good players here and I really wanted to try and do my best and help the team push on.
“I feel like I’ve played well this season, but I still think there’s more to come and I’m looking forward to the future with Blackburn Rovers.
“It’s been 20-odd games in a row I’ve played, which is great. At my age, after the injury I got last season, it’s definitely what I needed and I’m just ready to kick on again and keep going.”
Gestede, 25, arrived from Cardiff City at the end of November and after shaking off a slight thigh strain he had when he first joined, has gone from strength to strength.
The French-born Benin international made a huge impact as a substitute against Birmingham City last month, before grabbing his first Rovers goal on New Year's Day at Elland Road – a towering header from a Cairney corner.
“I am very happy to sign for Blackburn Rovers,” said Gestede. “They gave me the chance to play and to be on the pitch and now they have given me the chance to sign a permanent deal and I’m delighted to take it.
“It’s a big club and so I’m very happy to stay here. Everybody was very welcoming with me when I joined. They tried to make me feel at home and that’s happened.
“The lads have been very nice, the staff have been very nice with me, people in the club have been very nice, so I’m very happy and I hope I will enjoy my time here.
“I trust in my team-mates and we are very close to the play-off places, so if we keep playing like we have and keep believing in ourselves, we can do something.”