Benfica football tickets are available to be purchased on the official site here. They are also sold within the stadium precinct in designated ticket offices and in the official Megastore, however it's more prominent to see tickets for the B football team and other sports such as futsal, basketball, volleyball and hockey in the Megastore, which is opposite the Adidas store.
Benfica members (or sócios) are given priority for home tickets and lastly the general public. You will almost always find tickets on sale to the general public a few days before the match, however, it depends on demand.
To purchase a season ticket you must hold a Benfica membership.
The basic season ticket called RedPass gives you access to all first team football matches at the Estádio da Luz and a higher priority to purchase away tickets than sócios without a season ticket. It also has a range of benefits such as discounts in stores and extra free tickets to invite your family and friends.
There are a variation of RedPass' which can also give you access to other Benfica sports and first team football cup matches. The inner details may vary season to season. Please consult the official website for more information.
Outside single or season tickets, the club may offer promotional packs and sell tickets in a group, for example all group stage games for the Champions League or even a bundle of Liga games at once.
There are also new initiatives to bring more supporters to the stadium that appear season to season at the club's discretion.
To avoid disappointment always buy your ticket in advance, even though the Estádio da Luz rarely sells out in the domestic league, in the exception of rivals Sporting CP and FC Porto.
Never buy from online ticket agencies unless the club has confirmed on its website that the match is fully sold out. Online ticket agencies will generally charge you 5x more than the face value of the ticket, and are usually on sale even though the club are still selling tickets at the normal price.
If you are coming from abroad, register on the official website and purchase your tickets and select the stadium pick-up option which is relatively stress free, however it is recommended you pick up the tickets at least 2 hours before kick-off to avoid the queues.