Disney-owned US broadcaster ABC suspended Kimmel's show on September 17 over comments he made about the assassination of conservative activist Charlie Kirk.
Sinclair, which is known for conservative political content, had called on Kimmel to apologise to Kirk's family - and taking it a step further, asked him to "make a meaningful personal donation" to Turning Point USA, the nonprofit that Kirk founded.
Sinclair is one of two major broadcast owners that had not agreed to resume airing the show this week after Disney lifted a nearly week-long suspension.
It had faced pressure from some politicians over the decision to not air the program.
Sinclair's ABC stations represent about 14 per cent of US households.
Nexstar Media Group has also opted to keep Kimmel off the air on its 32 owned-and-operated ABC stations, which account for about nine per cent of US households.
Nexstar needs FCC approval for a $US6.2 billion ($A9.5 billion) merger with Tegna.
Hours before the ABC's suspension, Federal Communications Commission chair Brendan Carr warned that local broadcasters who aired Kimmel could face fines or loss of licences and said "it's time for them to step up".
Disney and Carr did not immediately comment on Sinclair's decision.
with AP
