| faux queen | | | |
| feast or famine | | | |
| feathered friend | | | |
| feathered oof-bird | | | |
| feather in one's cap | | | |
| featherless biped | | | |
| feather one's nest | | | |
| federal case | | | |
| fed up | | | |
| feeding frenzy | | | |
| feed off | | | |
| feed the dragon | | | |
| feed the fire | | | |
| feed the meter | | | |
| feed two birds with one scone | | | |
| feel around | | | |
| feel for | | | |
| feel free | | | |
| feel one's way | | | |
| feel out | | | |
| feel someone's collar | | | |
| feel the pinch | | | |
| feel up | | | |
| fee simple absolute in possession | | | |
| feet first | | | |
| feet of clay | | | |
| fence in | | | |
| fencepost problem | | | |
| fence-sit | | | |
| fence the tables | | | |
| fend and prove | | | |
| fend away | | | |
| fetch a compass | | | |
| fetch and carry | | | |
| fetch way | | | |
| fever pitch | | | |
| few and far between | | | |
| few cards shy of a full deck | | | |
| few sandwiches short of a picnic | | | |
| fickle mistress | | | |
| fiddle while Rome burns | | | |
| field day | | | |
| fifth-rate | | | |
| fifth wheel | | | |
| fifty-cent tour | | | |
| fight a losing battle | | | |
| fight fires | | | |
| fight fire with fire | | | |
| fight for one's life | | | |
| fighting chance | | | |
| fighting spirit | | | |
| fight one's corner | | | |
| fight shy | | | |
| file away | | | |
| file off the serial numbers | | | |
| fill in | | | |
| fill in the blank | | | |
| fill one's boots | | | |
| fill one's face | | | |
| fill one's hand | | | |
| fill someone's shoes | | | |
| fill up | | | |
| filter down | | | |
| filter up | | | |
| filthy lucre | | | |
| filthy rich | | | |
| final cut | | | |
| final nail in the coffin | | | |
| final say | | | |
| find another gear | | | |
| finders, keepers | | | |
| finders, keepers; losers, weepers | | | |
| find fault | | | |
| find it in one's heart | | | |
| find one's ass with both hands and a flashlight | | | |
| find oneself | | | |
| find one's feet | | | |
| find one's place | | | |
| find one's tongue | | | |
| find one's voice | | | |
| find out | | | |
| find the net | | | |
| fine-feathered friend | | | |
| fine feathers make fine birds | | | |
| fine line | | | |
| fine print | | | |
| finer things | | | |
| finest hour | | | |
| finger in the pie | | | |
| finger to the wind | | | |
| finish with | | | |
| F in the chat | | | |
| fire-breathing | | | |
| fire drill | | | |
| fire hose | | | |
| fire in the belly | | | |
| fire on all cylinders | | | |
| fire sale | | | |
| fire the starting gun | | | |
| firing line | | | |