With accent marks:
Рыба́к рыбака́ ви́дит издалека́.
A fisherman sees a fisherman from afar.
Today we understand this proverb as "people with similar interests will always find a common language". In this sense, the closest English equivalent would be "birds of a feather flock together".
Although in the original version, the meaning of the proverb was much closer to the modern joke "a fisherman hates a fisherman from afar". Because in the full version, it sounded like this: "Рыбак рыбака видит издалека, потому и стороной обходит" (a fisherman sees a fisherman from afar, therefore he avoids him).
Other Russian proverbs
A holy place is never empty.
The best is the enemy of the good.
A bird is visible by its flight.
One in the field is not a warrior.
When I eat I am deaf and mute.
One head is good, but two ones are better.
If I knew where I would fall, I would lay some straw there.
All is well that ends well.