Dice the peaches and avocado. Finely chop the red onion, cilantro, and jalapeno. Juice the lime.
Add all ingredients together in a bowl and season to taste.
Notes
Making in advance: Since peaches and avocado can soften quickly, this salsa best enjoyed fresh. For the best texture and flavor, it's recommended to make it no more than a few hours ahead. If prepping ahead, store it in an airtight container in the fridge and wait to add the avocado until just before serving to prevent browning. You can also toss the ingredients with a little extra lime juice to help keep everything fresh.Storing leftover salsa: Store peach salsa in an airtight container in the refrigerator for up to 2 days. To help prevent browning, press a piece of plastic wrap directly onto the surface before sealing the container.