Do I report a foreign retirement account like a UK ISA, Canadian TFSA, or Australian super on the FBAR?

Generally yes for the FBAR, and the tax treatment is a separate, thornier question. Foreign retirement and tax-advantaged savings accounts are typically foreign financial accounts, so they count toward your FBAR threshold and often toward Form 8938 as well. The catch is that the U.S. usually does not honor the home country's tax-favored status: a UK ISA, a Canadian TFSA, or an Australian superannuation fund may be fully taxable to you in the U.S. on its internal earnings, and some, like certain super funds or ISAs holding pooled investments, can even raise PFIC or foreign-trust issues. Treaties occasionally soften pension treatment but rarely these savings vehicles. This is one of the most misunderstood areas for immigrants. Report the accounts, and get cross-border tax advice on the income treatment before assuming they are tax-free.