Hi,
My former roommates got kicked out at the end of January. They had not paid the 215 per person we had agreed on two months earlier. When they got kicked out they left some things behind,and I had told them I had no problem giving their things back when they paid the 300 dollars they owed. I ended up giving their things to them before they paid the money. Is there anything I can legally do to make them pay me what they owe?

If you paid their share of the rent to the landlord then yes, you can sue them for it.

Who's names were on the lease and who kicked them out? You can not legally hold belongings in leiu of back rent.

... You can not legally hold belongings in leiu of back rent.

Landords cannot distrain personal property pending payment of the rent in most places. But OP was not a landlord, unless the roommate was a subtenant).

But it's academic. OP gave the stuff to the roommate.