The former hedge fund manager sees Kasich — who did not win any nominating contests Tuesday — as the best establishment alternative to Trump.
"I compared that to candidates on both sides and the delta is so huge. It's a no-brainer to me who would make the best president and it's clearly to me Governor John Kasich," Druckenmiller said.
The biggest test for whether Kasich can stay in the race comes on March 15, when Ohio and Florida hold their winner-take-all primaries.
Appearing with Druckenmiller on CNBC, Kasich predicted he would win in his home state. He said Sen. Marco Rubio needs to also win his home state of Florida to rationalize not dropping out.
Sen. Ted Cruz, seen as the outsider alternative to Trump, won his home state of Texas on Super Tuesday. He also picked up victories in Oklahoma and Alaska, despite former Alaska governor and ex-vice presidential candidate Sarah Palin's endorsement of Trump.
Home Depot co-founder and billionaire Ken Langone also joined Druckenmiller and Kasich on CNBC. Langone — who was a supporter of Chris Christie before the New Jersey governor left the race — also threw support behind Kasich.
Addressing Kasich, Langone said: "You've got a fabulous CV, the best. You're done a great job as CEO in Ohio. You go out to Cleveland, it's like an infant city. It's booming."
Langone complimented Kasich on showing "decency and maturity" and not going into the mudslinging with Trump and Rubio. "I looked the other night and I thought it was two 5-year-olds in a sandbox spitting at each other."
"We need to restore the faith of the American people in their leaders. This is what this is all about," Langone said. "We're going to work like hell to give you a shot."