Resources
Potentially useful links promoting mathematics and statistics beyond the conference
Competitions
The Mathematical Contest in Modeling (MCM)® The Interdisciplinary Contest in Modeling (ICM), a contest for high-school and undergraduate students (US and international)
MathWorks Math Modeling Challenge, a competition for high-school students (US and England). See a brief video here.
SIMIODE: a community (students/faculty, US/international) for Systemic Initiative for Modeling Investigations and Opportunities with Differential Equations. This includes Challenge Using Differential Equations Modeling
Putnam competition for undergraduate students in US and Canada (but with past problems and solutions available to all)
Mathematical olympiads (high-school or lower). See for example AMC. Your professors/teachers should be able to assist you in locating the proper olympiad in your country.
Research opportunities
The list of research experience for undergraduate programs: Math REU Programs and NSF REUs. Most are for US citizens/permanent residents only, but some allow international students.
Polymath Junior Collaborative summer research experience for undergraduate students (US and international)
Associations, unions and other communities
While many associations require paid memberships, student membership is often deeply discounted or can even be for free. Students in US (and elsewhere) are encouraged to talk to faculty members in their department as their university may offer membership for all faculty/students.
Many countries have various mathematics and statistics organizations. We cannot list them all but ask your professors who should be able to help you locate one in your region.
http://www.ams.org/membership/membership/mem-reciprocity: A convenient list of website links to various mathematics organizations around the world that have reciprocity agreement with the American Mathematical Society.
COMAP offers free memberships to students
Conferences
Check out calendars of the above associations as many of them organize regular and frequent conferences, in the US, internationally as well as online; see for example SIAM.
Online Undergraduate Resource Fair for the Advancement and Alliance of Marginalized Mathematicians
International E-Conference on Mathematical and Statistical Sciences
Math from around the web
Originally compiled from the list by Tom Edgar
YouTubers
Vi Hart
3blue1brown
Tibees
Mathologer
Stand-up Maths
PhysicsGirl
Mind Your Decisions
blackpenredpen
Eddie Woo
Michael Penn
Singing banana (James Grime)
Trefor Bazett
Quanta magazine
Vsauce
Zach Star
Up and Atom
ProfOmarMath, interesting facts and has a series about the subject test GRE
Sparks Math, using Geogebra to build very cool visualizations
That Math Thing discusses things relevant for students wanting to attend graduate school (or are in graduate school)
Dr. Weselcouch, math and minecraft
Podcasts
TikTok
Blogs
Traditional Media (TV, movies, etc.)
See the database maintained by Alex Kasman