Most likely yes, but in most cases, you can get the visa on arrival either at the land border or at the airport in Kathmandu. There is also the option of filling out the information and uploading a picture online before you arrive at: https://online.nepalimmigration.gov.np/
This can only be done within 15 days of your arrival, and you will need to print out the receipt with the bar code on it (you can't just show it on your phone). At the Kathmandu Airport there are computer stations where you can fill out the form online and it will take a picture for you. You can also do it the old fashion way and bring a visa photo and fill out the paper form at the airport.
Visa fees are:
$25 USD for 15 days
$50 USD for 30 days
$125 USD for 90 days
You can extend the visa for $2 per day with a minimum of 15 days at the immigration office in Kathmandu or Pokhara. You can fill out the form online like you do for the visa at the same website.
For the most up to date information on Nepal visas go to: http://www.nepalimmigration.gov.np/page/visa