Many fonts on Typekit support Czech. You can browse fonts that support Czech by selecting "Czech" from the list of supported languages in the sidebar under browse fonts.
In order to serve fonts in Czech, you must enable the "all characters" set in your kit. All fonts that support Czech include (at minimum) the following letter characters:
| A | B | C | D | E | F | G | H |
| I | J | K | L | M | N | O | P |
| Q | R | S | T | U | V | W | X |
| Y | Z | a | b | c | d | e | f |
| g | h | i | j | k | l | m | n |
| o | p | q | r | s | t | u | v |
| w | x | y | z | Á | Ä | É | Í |
| Ó | Ö | Ú | Ü | Ý | á | ä | é |
| í | ó | ö | ú | ü | ý | Č | č |
| Ď | ď | Ě | ě | Ň | ň | Ř | ř |
| Š | š | Ť | ť | Ů | ů | Ž | ž |