ROBERT Downey Jr paid tribute to his wife on their 10th wedding anniversary.

The 50-year-old actor is celebrating 10 years of wedded bliss with film producer Susan, 41, and took to Instagram to share his joy.

Posting a sweet picture of them together, he wrote: "A perfect 10. Happy Anniversary, Mrs. Downey."

Robert and Susan met on the set of 2003 movie 'Gothika' before getting engaged later that year.

The 'Iron Man' actor credits Susan with helping him to kick his drug and alcohol addiction, previously saying: "The old saying is true - behind every good man there's an incredible woman. I owe a huge amount - if not all - of my success to Susan. We make a great team, and all that luck I spoke about, that's Susan."

They have two children Exton, three, and nine-month-old daughter Avri while Robert has a 21-year-old son, Indio, with his first wife Deborah Falconer.

Robert and Susan also started the Team Downey production company together in 2010.