Do i need stitches if i cut my finger?

Depends: If it is a fresh cut (lac) and when you close (approximate) the edges the are better held together than without tension. Often we use a butterfly bandage or steri-strips on fingers and small lacs. Make sure it's clean and tetanus up to date.

Possibly.: May need stitches if wound depth > 1/4”, wound edges are gaping or jagged or if fat / muscle is visibly extending from wound. If you can’t stop bleeding that requires medical intervention.See: http://www.mayoclinic.org/first-aid/first-aid-cuts/basics/art-20056711