Smith's agent, Marc Cornstein, wouldn't disclose terms of the agreement -- it's likely nonguaranteed -- but he called the opportunity "a dream come true for Chris."
"We are very excited about him joining the Knicks and look forward to him getting a real opportunity to contribute," Cornstein told ESPNNewYork.com.
"He's now going to have to work extremely hard and establish himself as part of this veteran team."
On Wednesday, J.R. tweeted a photo of Chris signing his contract.
Chris Smith, a point guard out of Louisville, played for the Knicks' summer league team in Las Vegas.
A source familiar with the situation said the Knicks acquired Smith so they could assign his rights to their D-League team, the Erie BayHawks.
"The D-League is an option, as it is for all rookies," Cornstein said.
Information from ESPN New York's Ian Begley was used in this report.