I don't believe that there is any controversy in who wrote the book of Romans. It was inspired by God and written by Paul. Romans 1:1
I guess there is some controversy in that some believers don't believe the Bible is inspired by God.
2 Timothy 3:16 settles it for me.
Who was it written to? According To Romans 1:7 it is was written to the saints at Rome.
Romans 16:22 Tells us that Tertius wrote the letter for Paul.
Next we will look into when Paul wrote the letter of Romans.