Holder, who is also the team's ODI captain, was unanimously chosen as the leader in the longer-format format after Ramdin faced the axe within 15 months of being appointed as Test skipper.
A WICB media release stated that Holder's appointment "was recommended by the selection panel and endorsed unanimously by the directors during a teleconference meeting."
Opening batsman Kraigg Brathwaite will be Holder's deputy in the two-match Test series tarting October 14.
Holder has only played eight Tests so far. He has made 380 runs at 34.54, and taken 16 wickets at 35.37 with his pace bowling. He took over the ODI captaincy with only 21 matches behind him.
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"We expect to get new thinking and new dynamism from him," said Lloyd.
"Jason commands respect. He is a fine young man, very intelligent and he seems to get the best from the players because he is a straightforward guy. I think the players will warm to him. He has a young bunch of players and we feel he can guide them in the manner that is required for internationals.
"We do not want to any captain to lead in all three formats just now. It would be quite burdensome on anyone. We think we can have a separate Twenty20 captain," the two-time World Cup winning captain added.
"I have spoken to Denesh and he understood the situation and there was no animosity," Lloyd said.
"We just want him to perform a little bit better right now, particularly with the bat, and give of his best and support the new captain," he added.
West Indies squad: Jason Holder(captain), Kraigg Brathwaite (vice-captain), Devendra Bishoo, Jermaine Blackwood, Carlos Brathwaite, Darren Bravo, Rajindra Chandrika, Shane Dowrich, Shannon Gabriel, Shai Hope, Denesh Ramdin, Kemar Roach, Marlon Samuels, Jerome Taylor, Jomel Warrican.