During development, signaling networks specify stomatal cell fate and patterning in response to phytohormones. A number of studies in the past few years have revealed that brassinosteroids repress the signaling pathway that inactivates SPEECHLESS (SPCH), promoting stomatal cell fate determination in the hypocotyl. These plant hormones also control stomatal patterning specification by regulating genes in the TTG/BHLHs/MYBs/GL2 network. Gibberellins, like brassinosteroids, promote stomatal formation in the embryonic stem, which suggests that their signaling pathways may converge. These phytohormones also regulate LLM-domain B-GATA factors. The involvement of these factors as positive regulators of stomatal formation, which function upstream of SPCH, suggests that the brassinosteroid and gibberellin signaling pathways may converge to control stomatal cell fate specification. In addition, the leucine-rich repeat-containing receptor-like protein TOO MANY MOUTHS acts later than these hormones in the cell division sequence that triggers stomatal formation, and it also appears to control stomatal initiation in response to brassinosteroids. The emerging picture suggests that crosstalk among hormones and signaling networks guides stomatal cell fate determination and patterning in the hypocotyl.