Public Health Scotland publishes a daily cumulative total for each Scottish region.
Forth Valley’s total had remained in double figures from December 7 through to the 22st.
But, the incremental increases have now shown the first big spike.
The data comes as NHS Forth Valley launches a campaign to encourage everyone over 18 to get their booster “before the bells.”
Dr Graham Foster, director of public health, said: “Getting boosted by the bells is the best way to keep you and your loved ones safe and protect the NHS.”
Latest published figures show 73.5% of eligible adults aged 18 and above in Scotland have now received their booster or third dose, giving them the best possible protection against coronavirus.
Forth Valley’s omicron total compares with 271 in Fife and 248 in Tayside.
In Ayrshire and Arran, the total stands at 433.