Young Money -- Yes, We're In Business with Cristiano Ronaldo!

Young Money Entertainment is definitely in business with Cristiano Ronaldo ... this according to a rep for Lil Wayne's company ... who tells TMZ Sports they already have a project together set for this week.

TMZ Sports broke the story ... Weezy is starting his own sports management company and Ronaldo is client numero uno.

Ronaldo tweeted that there will be NO changes to his current management team -- which we're told is partially true ... no one is getting fired. He's just adding Young Money to handle branding, marketing and other sports management issues in the United States.

In fact, a rep for Young Money tells us Wayne and Ronaldo are 100% working together.

Stay tuned ...