Cruickshank will lead all of NatMags' online properties, including cosmopolitan.co.uk and netdoctor.co.uk, and the Handbag group of websites.
She will report to Duncan Edwards, chief executive of The National Magazine Company.
The role is primarily UK focused, but Cruickshank will also have international responsibility including assessing acquisitions, and the export of UK web brands abroad.
In June, NatMags announced it was searching for a managing director of digital publishing to oversee the creation of a network of online products, including magazine brand extensions and standalone sites.
The appointment of Cruickshank now means this role has been filled, but with a bigger remit than originally planned. In March this year NatMags acquired consumer health site netdoctor.co.uk, and last week announced the acquisition of Handbag.com and sister sites getlippy.com, allaboutyou.com and gomamatoday.com.
Cosmopolitan, Good Housekeeping and Country Living have just launched new sites as part of NatMags' overhaul of its digital strategy and the majority of the magazine brands will receive similar treatment.
Media Week revealed in June that Handbag Group, as part of Press Holdings, was considering a launch in the US. This week Cruickshank said: "We are still looking really seriously at that. One of the big challenges would have been recruiting a team from scratch in the US, but if we decide to do it now we have the platform there and the expertise already (through Hearst). We will look at all international opportunities, not just the US."
She added: "We are still very serious about looking at other acquisitions, looking at the right types of businesses to bring into the network."
Cruickshank said the company "was not simply going to launch a website for every magazine - they will be complementary".
The structure of Handbag and NatMags' digital staff has yet to be decided, but they will work together in a new Hearst Digital Network office in London's West End.