Marriage requirements for Mexico

Foreigners Getting Married to Foreigners: You don't need to be resident in Mexico in order to get married there, you'll just need a passport and your tourist permit, plus some other paperwork (see below). If you plan to get married to a Mexican in Mexico

If you plan to marry a Mexican National in Mexico, you'll need to fulfil some additional requirements:

In addition to all of the above documentation, you will need to obtain permission from the "Secretaria de Gobernacion - Oficina de Migracion" where for a fee of around US$200/£130 you'll need to acquire a permit to marry a Mexican national. The document is known as "Permiso para contraer matrimonio con un nacional".
The office issuing this permit must be the same office that has jurisdiction over the area where the marriage is to take place - so check beforehand!
This process can take from two days to two weeks, depending on the State and the people at the local government office: be prepared to be patient if you have to! Foreigners wishing to marry a Mexican citizen must first obtain permission to do so from the "Instituto Nacional de Migración" Secretaria de Gobernación (Ministry of Interior).

Marriage Fees

You will need to pay your Marriage License fee (approx £20/US$30*), allow the waiting period to go by (anything from 30 minutes to a few days, depending on the State), and then the ceremony can take place and the marriage will be legal.
The least expensive option is to have the ceremony performed at the Local Registry Office. For a further fee, you can arrange for the ceremony to take place elsewhere (hotel, beach, colonial mansion, etc). You will need to make further arrangements with all parties involved, or instruct your Wedding Planner to arrange this on your behalf.
Once the civil ceremony has been completed, you will need to obtain a certified copy of the marriage certificate (Acta de Matrimonio). This will prove that you have been legally wed in accordance with Mexican law, and the marriage will be recognised just about everywhere in the world where it can be, including the USA, Canada, United Kingdom / EU.
Word is, that local authorities in Cancun are charging foreigners a disproportionate fee of US$600 (£420) for a permit to get married there (locals pay around US$30/£20).

Church Weddings: Are very difficult to arrange here for a variety of reasons, Firstly, the Mexican government recognizes only civil weddings; Secondly, the Roman Catholic Church (which predominates in this country)requires compliance with many formalities, which have proven be cumbersome in most cases. The civil judge, however, has no problem with a minister or lay person being present and speaking at the ceremony, on several occasions, protestant ministers (usually Presbyterian) have read from the bible, etc.

If you would like to get married in a church in Mexico, this can be arranged, although additional planning and fees will be required.