Toll-like receptor 7 (TLR7) signalling can induce potent anti-viral immunity; however, hyper-activation of this receptor in autoimmunity can have harmful effects. This is the case in conditions such as systemic lupus erythematosus (SLE). Several studies have investigated the benefits of blocking TLR7, or downstream signalling molecules, to ameliorate SLE pathogenesis. In the context of endogenous negative immune regulators, the tyrosine phosphatase SHP1 has been implicated for its ability to limit both innate and adaptive immune signalling pathways. By contrast, the highly homologous phosphatase SHP2 has primarily been found to enhance signalling, including TLR7-mediated pro-inflammatory cytokines, while its impact on TLR7-induced type I interferons (IFNs) has not yet been investigated. In addition, SHP1 has been shown to have differential effects downstream of TLRs 3 and 4, where it can block the expression of pro-inflammatory cytokines but promote type I IFN induction. This study sought to determine whether SHP1 had the same, or differential impacts, downstream of TLR7 signalling. To investigate this, we made use of plasmacytoid dendritic cells (pDCs), a cell type with high expression levels of TLR7 and no detectable expression of TLR8. Treatment of the pDC cell line CAL-1 with SHP1 inhibitors SSG and TPI-1, enhanced pro-inflammatory cytokines and IFNβ expression in response to R848-induced TLR7 activation, as determined by ELISA. Additionally, SHP2 inhibition with SHP099 also increased R848-mediated IFNβ production, indicating a novel role of SHP2 in the TLR7-IFNβ signalling axis. Through analysis of a publicly available RNA sequencing dataset from CAL-1 cells, we found that TLR7 activation led to the downregulation of SHP1 at the messenger (m) RNA level. We further confirmed this at the protein level by Western blot analysis. Similarly to the inhibitor studies, stable knockdown of SHP1 led to an increase in pro-inflammatory cytokine and IFNβ production by R848-stimulated CAL-1 cells. We discovered that SHP1 knockdown CAL-1 cells had increased levels of TLR7 and SHP2 as determined by Western blot; with SHP2 being important in the trafficking of TLR7 to the endosome for its activation. Using Western blot analysis, we gained further mechanistic insight into the SHP1-mediated regulation of the NF-κB and IRF signalling pathways. R848-stimulated SHP1 knockdown CAL-1 cells showed enhanced activation of the canonical NF-κB pathway and IRF5, potentially through its regulation of the upstream kinase IKKβ. This was deduced by the observed increase in IKKβ phosphorylation, enhanced degradation of the NF-κB inhibitor IκBα, increased phosphorylation of p65, and an upregulation in the nuclear levels of p50 and IRF5. In addition to this, we performed label-free quantitative mass spectrometry on nuclear lysates from control and SHP1 knockdown CAL-1 cells, in response to R848. This allowed us to uncover the impact of SHP1 deficiency on the nuclear proteomic landscape of CAL-1 cells. We initially determined that SHP1 was present in both the nuclear and cytoplasmic fractions of CAL-1 cells. We identified that knockdown of SHP1 in CAL-1 cells altered the levels of several nuclear and mitochondrial proteins. Proteomic data analysis showed increased levels of the antioxidant PRDX3, NF-κB activators PIN1, NAP1L1, ANXA1 and LSP1, as well as key proteins involved in fatty acid metabolism and glycolysis. Interestingly, the isomerase PIN1, which is involved in the aberrant immune responses in SLE, was more than 3-fold higher in nuclear lysates following SHP1 knockdown in CAL-1 cells. By contrast, we detected a reduction in proteins involved in Acetyl-CoA generation, oxidative phosphorylation, and negative regulation of TLR signalling, such as the serine/ threonine protein phosphatase 1 gamma (PP1G). These findings point towards a novel role for SHP1 in the regulation of the TLR7 pathway, highlighting a potential target for modulation in TLR7-associated diseases.