The Canadian Sentinel Practitioner Surveillance Network (SPSN) reported mid-season 2023/24 estimates of influenza vaccine effectiveness (VE) against influenza A(H1N1)pdm09 (63%, 95% CI: 51–72) and A(H3N2) (40%, 95% CI: 5–61). VE was lower against clade 5a.2a.1 (56%, 95% CI: 33–71) than against clade 5a.2a.26 (67%, 95% CI: 48–80). The Omicron XBB.1.5 vaccine provided comparable protection against medically attended COVID-19, with VE of 47% (95% CI: 21–65), and higher VE (67%, 95% CI: 28–85) among individuals with prior confirmed SARS-CoV-2 infection. The study highlights the importance of ongoing VE monitoring, especially with the evolution of Omicron variants.The Canadian Sentinel Practitioner Surveillance Network (SPSN) reported mid-season 2023/24 estimates of influenza vaccine effectiveness (VE) against influenza A(H1N1)pdm09 (63%, 95% CI: 51–72) and A(H3N2) (40%, 95% CI: 5–61). VE was lower against clade 5a.2a.1 (56%, 95% CI: 33–71) than against clade 5a.2a.26 (67%, 95% CI: 48–80). The Omicron XBB.1.5 vaccine provided comparable protection against medically attended COVID-19, with VE of 47% (95% CI: 21–65), and higher VE (67%, 95% CI: 28–85) among individuals with prior confirmed SARS-CoV-2 infection. The study highlights the importance of ongoing VE monitoring, especially with the evolution of Omicron variants.