It is not a daylily, notice the different foliage that grows up the stem. It is a tru lily of genus Lilium. There are a number of cultivars that look like that so can't say its name. It's very nice though..
As Connie said, the flowers are of a true lily (Lilium) not a daylily (Hemerocallis), but the foliage and buds on the right of the picture belong to a separate plant which is a daylily. Daylilies are not a kind of lily despite the common name. There is a lily forum here on NGA so you may want to post the picture of your Lilium there: