The 33-year-old joined the Spanish giants in 2009, and scored 450 goals in just 438 appearances for Los Blancos - including 311 in 292 La Liga appearances.
He's no stranger to incredible strikes, and we recount seven of his best from his time in Madrid...
7. Atletico Madrid 1-2 Real Madrid (2011/12)
An absolute stunner in what was a season of remarkable goals for Cristiano Ronaldo, the Portuguese maestro curled in an effort from five yards outside the corner of the box.
From the ball being played into him, the Real Madrid star took just two touches before dispatching an incredible strike into the far corner of Thibaut Courtois' net.
His second goal on the night, the strike gave the Los Blancos a 2-1 lead over city rivals Atletico Madrid. They went on to win 4-1.
6. FC Barcelona 1-2 Real Madrid (2017/18)
Capping of a flowing counterattack that started on the edge of Real Madrid's own box, Ronaldo showed off every inch of his athleticism and quality.
Catching up with the ball on the edge of the Barcelona box, a slick cut inside left Gerard Pique for dead - before Ronaldo curled a beauty of a strike into the opposite corner of the net.
Well beyond the reach of the goalkeeper, the goal gave Real Madrid a 2-1 lead in the Spanish Super Cup - in a game that would later see Ronaldo sent off, and shove the referee.
5. Malaga 0-4 Real Madrid (2011/12)
Confidence was flowing as Real Madrid dismantled a poor Malaga side inside the first half.
That could be seen no clearer than in Ronaldo's third goal, as he wrapped up a 15-minute hat-trick. With a corner headed down to the Portuguese forward, he twisted to extravagantly flick home the ball.
It was a cheeky finish, but one that showed all of his incredible talent - not only in the finish, but to manufacture several yards of space in all directions inside the Malaga six-yard box.
4. Real Madrid 3-1 Levante (2011/12)
Cristiano Ronaldo just couldn't stop scoring wonder goals - or hat-tricks - during the 2011/12 season, as he did it once more, against Levante this time.
Cutting the ball inside from the left wing, Ronaldo fired a powerful and yet deceptive shot over the Levante goalkeeper.
It was almost a lob of sorts, and left the opposition shotstopper with no chances. Real Madrid went on to win the match 4-2.
3. Real Madrid 2-0 Osasuna (2013/14)
Ronaldo's second goal of this match, the sheer power and accuracy the Portuguese star generated belies belief.
Cutting inside from the left wing, as he so often does, Ronaldo fired a strike from around 20 yards out arrow-straight into the top corner of the Osasuna net.
It was right in the postage stamp of the goal, unstoppable, and set Madrid well on their way to victory. They won the game 4-0.
2. Rayo Vallecano 0-1 Real Madrid (2011/12)
Many players score the only goal of a game. Few do it with the quite the audacity of Cristiano Ronaldo against Rayo Vallecano back in 2012.
With the scores goalless around the hour mark, Ronaldo latched on to a poor defensive header from a corner.
On the edge of the six-yard box, the Portuguese magician was forced backwards - facing away from goal - by the Rayo defenders and the danger looked past.
Not for Ronaldo, though, who pulled out a truly ridiculous and sublime backheel from almost the same distance as the penalty spot into the bottom corner.
1. Juventus 0-2 Real Madrid (2017/18)
It couldn't quite be a list of Cristiano Ronaldo's greatest goals for Real Madrid without mentioning that Champions League quarter-final goal against Juventus.
After an initial Lucas Vasquez strike was parried away, the ball was played back into the box and Ronaldo appeared with all his skill and ability.
Running back away from goal, he pulled out an overhead kick of the highest magnitude, leaving Gianluigi Buffon no chance as he watched the ball hit the back of the net.
Even the Juventus fans stood to applaud the goal. Now, they will be looking forward to applauding similar goals again, but this time coming in the famous white and black.