Blues captain John Terry gave his side a first-half lead when Willian’s free-kick dropped loose inside the box and he fired home via a deflection.
Tottenham had already hit the crossbar through Christian Eriksen, but Chelsea doubled their lead just after the break when Diego Costa’s shot was turned in by the leg of Kyle Walker.
Spurs pushed hard to find a way back in late on but Chelsea closed out the match to gain revenge for the 2008 final defeat to their London rivals and clinch a first trophy for manager Jose Mourinho since his return to Stamford Bridge.
With Nemanja Matic suspended, Mourinho made a surprising team selection that included Gary Cahill – one of four changes – alongside John Terry in defence, with Kurt Zouma moving into midfield.
However, it appeared to put the Blues out of sorts in the opening half and Tottenham looked capable of breaking the deadlock.
Spurs, complete with seven changes to the side knocked out of the Europa League by Fiorentina on Thursday, had their best chance after 10 minutes when Harry Kane’s trickery won a free-kick in a dangerous area and Eriksen rattled the woodwork from the set piece.
Both Nacer Chadli and Ryan Mason should have done better with wayward attempts off-target, and Eriksen also forced Petr Cech to save at a tight angle, but Terry – the seasoned finalist – put his side ahead on 45 minutes.
A mistake by Chadli, giving away a needless free-kick on the right-hand side, allowed Willian to swing in a dangerous set-piece that dropped for Terry to poke home beyond Hugo Lloris.
Chelsea stepped up their intensity in the second half and threatened early after the break when Cesc Fabregas forced Lloris to parry with a skillful bicycle kick inside the box.
And it was Fabregas who set up his side’s second, his incisive pass finding the run of Costa, and the Spaniard’s effort beat Lloris inside his near post after a deflection off Walker.
Chelsea looked impenetrable at the back, with Terry especially looking back to his brilliant best.
Eden Hazard almost made it three with a superb curler from the edge of the box but, with Lloris beaten, the ball flew just past the post.
Spurs threatened through Kane and substitutes Mousa Dembele and Erik Lamela late on, but it was not enough to prevent Mourinho becoming the most successful foreign manager in Capital One Cup history – clinching his third League Cup and his seventh piece of silverware in England.
Chelsea: Cech 7; Cahill 7, Terry 9, Zouma 7 Ivanovic 7; Ramires 6, Fabregas 8, Azpilicueta 6; Willian 6, Hazard 7; Costa 8
Subs used: Oscar 6, Cuadrado 6, Drogba 6
Tottenham: Lloris 7; Walker 6, Dier 6, Vertonghen 6, Rose 6; Mason 6, Bentaleb 6; Townsend 5, Eriksen 6, Chadli 5; Kane 6
Subs used: Dembele 6, Soldado 5, Lamela 6
Man of the Match: John Terry