Please post a photo so we can help more accurately.

here

That's Blackspot, a fungal disease. Its going to be common in the spring and fall, when weather is wetter.

where are you.. big city name...

in my MI ... the leaves will be falling off the plants in the next few weeks.. and they will be completely picked up.. and shipped off the property ...

and the canes will be cut back and sprayed with an appropriate fungicide to insure the plants break out clean in spring ...

when i had over 150 roses.. i HAD TO SPRAY about every six weeks combining the fungicide with a systemic insecticide ... the constant spraying was one reason i quit growing roses.. when the kids came a long ...

ken

prevention is the key.. you must be proactive next year ....

there is nothing you can do to save those leaves ... if you want.. you could cut them all off .... and at least make the plant look better ... ken

i’m in chicago , rosarian. i just planted bunch of roses. new dawn, pearly gates , and summer romance. everyone of them are doing great and so was this one. except i just noticed these. i’m so upset. cuz i really loved the old classic rose fragrance it provided. with just a few blooms my lawn was filled with rose smells. but now these brown spots

As Ken has stated, this is a fungal disease that MUST be managed to limit the damage it can do.

"Managing" it means starting early with preventative (fungicide) sprays applied at least every 2 weeks through the growing season, and removing any leaves that develop spots.

If you find you have roses that Blackspot badly (like the one in your photos) and you don't want to use fungicides to control disease, then replace the offending plant with one that is less disease prone. There are always better choices when you discover you've got a variety that gets too much disease.