There are indeed TEFL programs available online. Where you need to be more specific to get some links is at what level you want to find a program. There are certificates, diplomas, and degrees available that I'm aware of. Webster University offers an MAT online with a concentration in TESL and TEFL The big certification for ESL/EFL teachers is the CELTA. It's not normally online. Another consideration is exactly what you want to do with this certification. Requirements to teach ESL in a business setting are very different than those to teach in the public schools. Most valid programs will require some amount of supervised teaching - this makes online programs less common but they do exist. Give us some more information...
Again, do you want to teach English to students in a college? To students in a high school? Elementary students? Recent immigrants in a class at the local community center? Literacy classes at the county literacy association? Do you want to travel to Taiwan (etc.) and teach English as a second language to speakers of Taiwanese? Each of these is going to have a different set of requirements. Do you have a bachelor's degree? If not, then getting a master's degree is out of the question until you do. Are you a native English speaker? If not then there will be some limitations to what you can do in international English teaching but on the other side some advantages in bilingual education. Keep in mind too - TEFL is not "to teach English" in common terminology. That expression is used by those who teach literature and grammar. Their education is a minimum bachelor's in English with considerable coursework in education and they are licensed to teach in public schools. At the college level these folks who "teach English" have at least a master's in English and likely a PhD. TEFL and TESL and TESOL are to "teach English to those who don't speak English". Except in the public schools, this isn't generally a regulated profession. A native speaker of English can often enter this profession with a bachelor's degree in anything and a short training program in teaching methods. Outside of the academic world (teaching in schools), the most respected certification is the CELTA. In the academic world, an MA in TEFL, TESL, TESOL, etc. is often required.
University of Leicester has an online certificate program, as well as a Masters in TESL. UF offers an Undergraduate and Graduate online class in TESL, but not a certification. However, at the end of the class, you do get a "certificate" that you completed a TESL course. It was good enough for me to teach English in Japan for 3 years.
According to Bears' Guide, 15th edition: ASSOCIATE'S DEGREES: Saint Mary of the Woods College www.smwc.edu (BG15, 170) BACHELOR'S DEGREES: Central Queensland University www.cqu.edu.au (BG15, 103) Murdoch University www.murdoch.edu.au (BG15, 123) Saint Mary of the Woods College www.smwc.edu (BG15, 170) University of Saskatchewan www.usask.ca (BG15, 144) Southwestern Adventist University www.swau.edu (BG15, 173) Washington State University www.wsu.edu (BG15, 150) MASTER'S DEGREES: Aston University www.aston.ac.uk (BG15, 98) Deakin University www.deakin.edu.au (BG15, 108) University of Manchester www.man.ac.uk (BG15, 178) University of Melbourne www.unimelb.edu.au (BG15, 140) University of North Dakota www.und.edu (BG15, 179) Oxford Brookes University www.brookes.ac.uk (BG15, 166) Regent University www.regent.edu (BG15, 168) University of South Africa www.unisa.ac.za (BG15, 144) DOCTORAL DEGREES: University of Melbourne www.unimelb.edu.au (BG15, 140)
