Supposed to make lemon thyme risotto and chicken, can't find lemon thyme! Any suitable replacement herb?

Or you could just use thyme. Lemon thyme really doesn't have that pronounced a flavor. I like HLA's suggestion of lemon verbena which is delicious but practically impossible to find unless you grow it yourself.

hla beat me to it. I'd mix thyme and lemon zest. In fact, I have done that.

A mix of thyme and lemon zest would likely be the most accessible (I'd probably go 3/4 thyme and 1/4 lemon, then add more lemon to taste). You could also use lemon balm or lemon verbena in place of the lemon zest.